U.S. patent application number 11/679182 was filed with the patent office on 2007-09-27 for catheter securement device.
Invention is credited to William D. Hare, Russell A. Houser.
Application Number | 20070225642 11/679182 |
Document ID | / |
Family ID | 38534452 |
Filed Date | 2007-09-27 |
United States Patent
Application |
20070225642 |
Kind Code |
A1 |
Houser; Russell A. ; et
al. |
September 27, 2007 |
Catheter Securement Device
Abstract
A coupler is configured to connect a first tubular vessel to an
aperture in a second tubular vessel. The coupler includes one or
more radially extending members and a substantially nonmetallic
tubular member. The substantially nonmetallic tubular member
include an outer wall, an inner wall defining a lumen having an
open distal end and an open proximal end, and a circumferential
ridge encircling the outer wall, the radially extending members
extending from the distal end of the tubular member. A method of
fabricating a coupler the method including fabricating radially
extending members; placing the radially extending members within a
mold; injecting a material into the mold; allowing the material to
cure to form the c coupler; and removing the coupler from the mold.
The coupler includes a tubular member having an outer wall, an
inner wall defining a lumen having an open distal end and an open
proximal end, and a circumferential ridge encircling the outer
wall. The radially extending members extend from the distal end of
the tubular member.
Inventors: |
Houser; Russell A.;
(Livermore, CA) ; Hare; William D.; (Princeton,
NJ) |
Correspondence
Address: |
WILLIAM DOUGLAS HARE
3 ANDERSON LANE
PRINCETON
NJ
08540
US
|
Family ID: |
38534452 |
Appl. No.: |
11/679182 |
Filed: |
February 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10326211 |
Dec 20, 2002 |
7182771 |
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11679182 |
Feb 27, 2007 |
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60341160 |
Dec 20, 2001 |
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60369835 |
Apr 5, 2002 |
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60381805 |
May 21, 2002 |
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60385216 |
May 31, 2002 |
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60394793 |
Jul 9, 2002 |
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60399710 |
Aug 1, 2002 |
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60428509 |
Nov 22, 2002 |
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Current U.S.
Class: |
604/93.01 |
Current CPC
Class: |
A61B 2017/1135 20130101;
B33Y 80/00 20141201; A61B 2017/1157 20130101; A61B 2017/1107
20130101; A61B 17/11 20130101; A61B 2017/00243 20130101; A61M 39/10
20130101; A61B 17/115 20130101; A61B 17/0644 20130101 |
Class at
Publication: |
604/093.01 |
International
Class: |
A61M 39/10 20060101
A61M039/10 |
Claims
1-20. (canceled)
21. A catheter securement device comprising: a tubular stem having
a channel passing between a first end having a first opening and a
second end having a second opening, the channel having an inner
surface having a first diameter and the tubular stem having an
outer surface having a second diameter, and a metallic strain
relief positioned within the stem; an outer ridge positioned around
the outer surface of the stem having an outer surface having a
third outer diameter and being connected to the stem by a proximal
edge and a distal edge, the third outer diameter and the proximal
edge and the distal edge extending outwardly from the stem to the
third outer diameter; and a tubular connecting member extending
from the outer ridge, having a second channel passing between a
first end having a first opening and a second end having a second
opening, the second channel having an inner surface of a fourth
diameter and the connecting member having an outer surface of a
fifth diameter, and the first end of the tubular connecting member
being connected to the second end of the tubular stem.
22. The catheter securement device of claim 21, wherein the
metallic strain relief comprises a superelastic material.
23. The catheter securement device of claim 21, wherein the outer
ridge further comprises a metallic ring having at least a portion
of the ring positioned within the outer ridge between the outer
surface and the stem.
24. The catheter securement device of claim 23, wherein the
metallic ring comprises a superelastic material.
25. The catheter securement device of claim 21, further comprising
at least one inner ridge extending inwardly from either or both of
the first channel in the tubular stem or the second channel in the
connecting member, the inner ridge having an inner diameter less
than the inner diameter of the channel from which it extends.
26. The catheter securement device of claim 25, wherein the inner
ridge comprises a flap or valve.
27. The catheter securement device of claim 21, wherein the device
comprises a single molded piece.
28. The catheter securement device of claim 21, wherein the tubular
connecting member further comprises a ring.
29. The catheter securement device of claim 28, wherein the ring
extends around the second channel between the inner diameter and
the outer diameter of the channel.
Description
RELATED APPLICATIONS
[0001] This application claims priority as a continuation of U.S.
patent application Ser. No. 10/326,211 filed on Dec. 20, 2002, the
entirety of which is incorporated herein by reference, scheduled to
issue on Feb. 27, 2007 as U.S. Pat. No. 7,182,771, and which claims
priority from U.S. Provisional Patent Applications 60/341,160 filed
on Dec. 20, 2001 and titled Vascular Connectors, Techniques,
Methods, and Accessories; 60/369,835 filed on Apr. 5, 2002 and
titled Vascular Couplers, Techniques, Methods, and Accessories;
60/381,805 filed on May 21, 2002 and titled Vascular Couplers,
Techniques, Methods, and Accessories; 60/385,216 filed on May 31,
2002 and titled Anastomic Coupler with Valve; 60/394,793 filed on
Jul. 9, 2002 and titled Sutured Anastomotic Coupler Device and
Method of Use; 60/399,710 filed on Aug. 1, 2002 and titled Vascular
Couplers, Techniques, Methods, and Accessories; 60/______ filed on
Sep. 3, 2002 and titled Vascular Couplers, Techniques, Methods, and
Accessories; and 60/428,509 filed on Nov. 22, 2002 and titled
Vascular Couplers, Techniques, Methods, and Accessories.
TECHNICAL FIELD
[0002] The field of the inventions generally relates to
cardiovascular and vascular devices, and, more particularly, to
vascular couplers.
BACKGROUND
[0003] Cardiovascular and vascular diseases are treated
pharmacologically, using interventional cardiology, and surgically.
For example, interventional, catheter-based treatments include
percutaneous transluminal coronary angioplasty ("PTCA") with an
angioplasty balloon to compress plaque to the wall of a coronary
vessel, placement of a stent in a vessel to maintain the patency of
the vessel, and atherectomy to use a cutting instrument to shave
off and remove plaque from the lumen of the vessel. Surgical
treatments include coronary artery bypass grafting procedures using
cardiopulmonary support, beating heart techniques, minimally
invasive approach, and robotically assisted instruments. In these
procedures, the surgeon may use traditional, endoscopic, and/or
laparoscopic instruments. In traditional coronary artery bypass
grafting, the surgeon uses sutures to anastomose a synthetic or
natural bypass vessel to, for example, the aorta at one end and a
coronary artery at the other end, or from the internal mammary
artery ("IMA") to a coronary artery. To form an anastomosis between
an internal mammary artery and a coronary artery, blood flow
through the internal mammary artery must be temporarily stopped,
typically by applying a removable clamp to the mammary artery. The
mammary artery is then severed downstream from the clamp to create
a free end. An incision is created in the target coronary artery
downstream of the blockage. The free end of the mammary artery can
then be connected to the incision in the coronary artery, typically
by suturing, such that blood can flow from the mammary artery
through the incision into the coronary artery. Typical traditional
coronary artery bypass grafting procedures involve aortic clamping
and a procedure time of approximately ten to twenty minutes per
anastomosis. Coalescent Surgical markets a superelastic/shape
memory suture that is used in an interrupted suture technique and
reduces the anastomosis time. Like traditional bypass procedures,
the superelastic/shape memory suture involves aortic clamping.
[0004] Some of the other devices used in beating heart and/or
minimally invasive surgical treatments are produced by companies
that include Advanced Bypass Technologies/Converge Medical, Inc.,
By-Pass, Cardica (formerly Vascular Innovations), Coalescent
Surgical, Corvascular, Ethicon, HeartPort, Heart-Tech,
Intellicardia, Onux Medical, Origin MedSystems, Inc. (Guidant), St.
Jude Cardiovascular Group (including Vascular Science), Sulzer
Carbomedics, Vasconnect, and Ventrica.
SUMMARY
[0005] In one general aspect, a coupler configured to connect a
first tubular vessel to an aperture in a second tubular vessel. The
coupler includes one or more radially extending members and a
substantially nonmetallic tubular member. The substantially
nonmetallic tubular member comprising an outer wall, an inner wall
defining a lumen having an open distal end and an open proximal
end, and a circumferential ridge encircling the outer wall, the
radially extending members extending from the distal end of the
tubular member.
[0006] Embodiments of the coupler may include one or more of the
following features. For example, the extending member may include a
first segment and a second segment, the first segment being at an
angle of 90.degree. or less with respect to the second segment, the
first segment extending from the tubular member. The second segment
defines a region that is wider than a region defined by the first
segment. The extending member may include a nickel titanium alloy
and/or 17-7PH stainless steel. The proximal end of the tubular
member may include a strain relief.
[0007] The coupler may further include at least one securing member
mounted to the distal end of the tubular member, the securing
member including a first segment positioned adjacent to the inner
wall, a second segment positioned against the outer wall, and a
third segment connecting the first segment and the second
segment.
[0008] The coupler may further include at least one securing member
mounted to the distal end of the tubular member, the securing
member including a first segment positioned adjacent to the inner
wall, a second segment positioned within the wall between the inner
wall and the outer wall, and a third segment connecting the first
segment and the second segment. The coupler may further include a
gasket extending from the distal end of the tubular member, the
radially extending members extending from the gasket. The tubular
member may include one or more of silicone, ePTFE, polyurethane,
and polyisoprene.
[0009] The coupler may further include a gasket extending from the
distal end of the tubular member and a strain relief extending from
the proximal end of the tubular member. The tubular member, the
ridge, the gasket, and the strain relief are an integral unit.
[0010] In another general aspect, a method of fabricating a coupler
the method including fabricating radially extending members;
placing the radially extending members within a mold; injecting a
material into the mold; allowing the material to cure to form the c
coupler; and removing the coupler from the mold. The coupler
includes a tubular member having an outer wall, an inner wall
defining a lumen having an open distal end and an open proximal
end, and a circumferential ridge encircling the outer wall. The
radially extending members extend from the distal end of the
tubular member.
[0011] Embodiment of the method may include one or more of the
following. For example, the method may further comprise inserting
one or more securing members at least partially within the mold.
Fabricating the radially extending members comprises etching a
sheet of a metal alloy. Fabricating the radially extending members
further comprises one or more of forming, annealing, chemical
polishing, and electropolishing. The material comprises one or more
of silicone, ePTFE, polyurethane, and polyisoprene.
[0012] Allowing the material to cure to form the tubular member
further comprises forming a ridge member around at least a portion
of a circumference of the tubular member, forming a strain relief
at the proximal end of the tubular member, and forming a gasket at
the distal end of the tubular member.
[0013] In another general aspect, a method of deploying a coupler
includes forming an opening in a wall of a tubular vessel;
deflecting the radially extending members into a longitudinally
extending configuration; inserting the extending members at least
partially into the opening; and releasing the extending members.
The coupler includes one or more radially extending members, a
substantially nonmetallic tubular member, the tubular member
comprising an outer wall, an inner wall defining a lumen having an
open distal end and an open proximal end, and a circumferential
ridge encircling at least a portion of the outer wall, the radially
extending members extending from the distal end of the tubular
member.
[0014] Embodiments of the method may include one or more of the
following features. For example, deflecting the radially extending
members into a longitudinally extending configuration further
includes deflecting the radially extending members and at least
partially inserting the extending members into an opening in a
deployment tool, the deployment tool including a handle and a
distal plate, the distal plate including the opening. Releasing the
extending members further includes placing the plate on the vessel
and removing the plate from around the coupler, the removal of the
plate allowing the extending members to return to the radially
extending configuration.
[0015] The couplers described herein enable clampless-bypass
surgery. By not utilizing a clamp on the aorta, this method has the
potential to significantly reduce the incidence of post surgical
neuro cognoscente dysfunction, which occurs in up to approximately
50% of patients undergoing coronary artery bypass grafting (CABG)
surgery.
[0016] Benefits that can be provided by the vascular couplers
described herein include: (1) a coupler system that enables
clampless bypass surgery--minimizing aortic manipulation by not
requiring cross-clamping or aortic side-biting during coronary
artery bypass grafting (CABG); (2) allowing or augmenting radial
vessel expansion and contraction similar to a sutured anastomosis;
(3) single piece coupler design in which no separate external
vessel component (e.g., collar) is required; (4) reinforced
anastomosis area (top vessel ridge) for strength; (5) limited
foreign material contact with blood or vessel (even with
non-everted version); (6) includes sutureless, sutured or
combination versions; (7) includes aortic (proximal), coronary
(distal), peripheral and valved versions for completeness; (8) does
not enlarge or expand punch hole or arteriotomy during deployment;
(9) once deployed, the coupler can ensure that all petals are in
contact with the inside vessel wall; (10) no introducer or plunger
is required for coupler deployment (although alternative versions
may utilize these or similar accessories); (11) ability to employ
multiple coupler deployment methods (push in, partially pull out;
twist and advance; forward deflected (superelastic) or forward
positioned (shape memory) petals, etc.); (12) much less costly to
use with respect to other current systems because there are fewer
components and accessories required; and (13) the coupler system is
easy to learn and easy to use.
DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a heart in which vascular
couplers are used to form a vascular bypass between the aorta and a
coronary artery.
[0018] FIG. 2 is a front perspective view of a vascular
coupler.
[0019] FIG. 3 is a bottom view of the vascular coupler of FIG.
2.
[0020] FIG. 4 is a top view of the vascular coupler of FIG. 2.
[0021] FIG. 5 is a cross-sectional side view of the vascular
coupler of FIG. 2.
[0022] FIG. 6 is a cross-sectional side view of the vascular
coupler of FIG. 2 with a hemostatic gasket mounted to the
coupler.
[0023] FIGS. 7a and 7b are perspective bottom and front views of a
deployment tool for deploying vascular couplers.
[0024] FIG. 7c is an enlarged perspective front view of the
deployment tool of FIG. 7a with a mounted vascular coupler.
[0025] FIG. 7d is a cross-sectional side view of a vascular coupler
implanted in a blood vessel, such as a coronary artery.
[0026] FIG. 8a is side view of a second deployment tool for
deploying vascular couplers.
[0027] FIG. 8b is an enlarged cross-sectional side view of the
second deployment tool deploying a vascular coupler.
[0028] FIGS. 9a and 9b are side and perspective side views of a
third deployment tool for deploying vascular couplers.
[0029] FIG. 10a is a perspective front view of a graft deployment
tool for placing a graft in a vascular coupler.
[0030] FIGS. 10b and 10c are cross-sectional side views of the
graft deployment tool placing a graft in a vascular coupler.
[0031] FIGS. 11-13 are front, cross-sectional side, and bottom
views of a vascular coupler.
[0032] FIG. 14 is a side view of the coupler of FIG. 11 implanted
in a vessel.
[0033] FIG. 15 is a cross-sectional side view of a vascular coupler
having a reinforcing ring and an enlarged hemostatic gasket.
[0034] FIGS. 16-18 are side, end, and top views of the components
used to fabricate the petals and securing members of a vascular
coupler.
[0035] FIGS. 19-21 are perspective front, cross-sectional side, and
bottom views of a vascular coupler having a wire petal.
[0036] FIGS. 22-24 are perspective front, top, and bottom views of
a vascular coupler having two wire petals.
[0037] FIG. 25 is a bottom view of a vascular coupler having four
wire petals.
[0038] FIG. 26 is a perspective side view of a vascular coupler
having wire or rod petals.
[0039] FIG. 27 is a perspective side view of the wire or rod
petals.
[0040] FIG. 28 is a bottom view of the vascular coupler of FIG.
26.
[0041] FIG. 29 is a bottom view of a vascular coupler having
generally T-shaped wire or rod petals.
[0042] FIGS. 30 and 31 are perspective front and bottom views of a
vascular coupler having U-shaped wire or rod petals.
[0043] FIGS. 32-36 illustrate bottom views of vascular coupler
having a variety of petal configurations.
[0044] FIGS. 37 and 38 illustrate bottom and side views of a
vascular coupler having overlapping petals.
[0045] FIGS. 39-42 are side, bottom, and cross-sectional side views
of vascular coupler formed at an angle of approximately 45.degree.
between the stem and the ridge.
[0046] FIGS. 43-45 are top, cross-sectional front, and
cross-sectional side views of a vascular coupler that includes
circumferential petals and longitudinal petals.
[0047] FIGS. 46-49 are perspective front, side, top, and
cross-sectional side views of a vascular coupler that includes
mounting clips.
[0048] FIGS. 50-52 are perspective front, front, and
cross-sectional front views of a valved coupler that includes a
base and a fitting that is configured to receive a bypass vessel
and be inserted into the base.
[0049] FIGS. 53-55 are perspective front, front, and
cross-sectional front views of the valved coupler of FIG. 50
illustrating the bypass vessel inserted into the base.
[0050] FIGS. 56 and 57 are cross-sectional side views of a closure
cap being inserted and inserted, respectively, in the valved
coupler of FIG. 53.
[0051] FIGS. 57-60 are top, side, and cross-sectional side views of
a stand-alone valve that can be easily implanted in tissue using a
minimally invasive surgical procedure.
[0052] FIGS. 61 and 62 are side and cross-sectional side views of a
vascular coupler that includes multiple petals that are oriented in
the general direction of the ridge.
[0053] FIGS. 63-65 are top, side, and perspective views of a single
wire or rod petal member.
[0054] FIG. 66 is a cross-sectional side view of a vascular coupler
incorporating the single wire or rod petal member of FIG. 63.
[0055] FIGS. 67-72 illustrate securing members that do not
penetrate tissue.
[0056] FIGS. 73-78 illustrate tissue penetrating securing
members.
[0057] FIGS. 79-81 are side, bottom, and cross-sectional side views
of a vascular coupler having longitudinal wire or rod petals
embedded in an overmolded ridge.
[0058] FIGS. 82-87 illustrate vascular couplers having
circumferential spring member in the stem.
[0059] FIG. 88 is a cross-sectional side view of a vascular
couplers having a groove configured to receive an everted end of a
bypass vessel.
[0060] FIGS. 89-92 are perspective and bottom views of a second
general class of vascular couplers based on non-overmolded
tubes.
[0061] FIGS. 93 and 94 are perspective and side views of a
non-overmolded vascular coupler having a slot.
[0062] FIGS. 95-98 are perspective, side, and bottom views of a
non-overmolded, angled vascular coupler having a slot.
[0063] FIGS. 99-102 are perspective, side, and bottom views of a
non-overmolded, angled vascular coupler having a slot and an
extended base.
[0064] FIGS. 103-107 illustrate various views of a deployment tool
for deploying, e.g., a non-overmolded, angled vascular coupler.
[0065] FIGS. 108 and 109 are perspective views of the deployment
tool of FIG. 103 deploying a non-overmolded, angled vascular
coupler.
[0066] FIGS. 109-116 illustrate various views of a non-overmolded,
angled vascular coupler having a partial longitudinal slot.
[0067] FIGS. 117 and 118 are side and perspective views of a
flat-sided vascular coupler.
[0068] FIG. 119 is a top view of the flat-sided vascular coupler of
FIG. 117.
[0069] FIG. 120 is a front view of the flat-sided vascular coupler
of FIG. 117.
[0070] FIG. 121 is a side view of the flat-sided vascular coupler
of FIG. 117 being inserted into an artery.
[0071] FIG. 122 is a perspective side view of the vascular coupler
of FIG. 117 inserted in an artery.
[0072] FIGS. 123 and 124 are top and perspective views of the
vascular coupler of FIG. 117 inserted into an artery.
[0073] FIG. 125 is a perspective front view of a vascular coupler
having V-shaped petals.
[0074] FIG. 126 is a top view of the vascular coupler of FIG.
125.
[0075] FIG. 127 is a front view of the vascular coupler of FIG. 125
implanted in a vessel.
[0076] FIG. 128 is a perspective front view of the vascular coupler
of FIG. 125 having a gasket.
[0077] FIG. 129 is a side view of the vascular coupler and gasket
of FIG. 128.
[0078] FIG. 130 is a top view of the vascular coupler and gasket of
FIG. 128.
[0079] FIG. 131 is a side view of the vascular coupler and gasket
of FIG. 128 implanted within a vessel.
[0080] FIG. 132 is a side view of another embodiment of a
deployment tool for deploying vascular couplers.
[0081] FIG. 133 is a front view of a vascular coupler having longer
and wider outer clips deployed in an artery.
[0082] FIG. 134 is a top view of the deployed vascular coupler of
FIG. 135.
[0083] FIG. 135 is a perspective side view of the deployed vascular
coupler of FIG. 134.
[0084] FIG. 136 is a perspective front view of a vascular coupler
having a notched gasket.
[0085] FIG. 137 is a top view of the vascular coupler of FIG.
136.
[0086] FIGS. 138 and 139 are side views rotated by 90.degree. of
the vascular coupler of FIG. 136.
[0087] FIG. 140 is a perspective view of a multi-element vascular
coupler having a gasket.
[0088] FIG. 141 is a top view of the multi-element vascular coupler
of FIG. 140.
[0089] FIG. 142 is a top view of the multi-element vascular coupler
of FIG. 140 taken at section line A.
[0090] FIG. 143 is a side view of the multi-element vascular
coupler of FIG. 140.
[0091] FIG. 144 illustrates a multi-element vascular coupler having
a longitudinal slot.
[0092] FIGS. 145 and 146 illustrate a multi-element vascular
coupler having wire and U-shaped petals and a longitudinal
slot.
[0093] FIG. 147 illustrates the vascular coupler of FIG. 144
implanted in a vessel.
[0094] FIG. 148 illustrates a vascular coupler having a partial
longitudinal slot.
[0095] FIG. 149 illustrates a vascular coupler having a complete
spiral slot.
[0096] FIG. 150 illustrates a vascular coupler having a multiple,
partial spiral slots.
[0097] FIG. 151 illustrates a compressed vascular coupler.
[0098] FIG. 152 illustrates a vascular coupler having the flexible
petals extended to reduce the profile.
[0099] FIGS. 153 and 154 illustrate a manual method of placing a
vascular coupler within a vessel.
[0100] FIGS. 155-162 illustrate various configurations of strain
relief members within vascular couplers configured to be placed in
a vessel without the use of petals.
[0101] FIG. 163 is a side view of a generic vascular coupler of
FIGS. 155-162 implanted in a vessel.
[0102] FIGS. 164 and 165 are cross-sectional side and end views of
the vascular coupler of FIG. 163 implanted in the vessel.
[0103] FIG. 166 is a top view of the vascular coupler of FIG. 163
implanted in the vessel.
[0104] FIGS. 167-175 illustrate various configurations of strain
relief members within the vascular couplers of FIGS. 155-162
configured to be placed in a vessel using petals.
[0105] FIG. 176 is a cross-sectional side view of the vascular
coupler of FIGS. 167-175 implanted in a vessel.
[0106] FIG. 177 is a top view of the vascular coupler of FIG. 176
implanted in the vessel.
[0107] FIG. 178 is a cross-sectional end view of the vascular
coupler of FIG. 176 implanted in the vessel.
[0108] FIGS. 179 and 180 are perspective views of reinforcing
members placed around bypass vessels connected to vascular
couplers.
[0109] FIGS. 181 and 182 are end and top views of the reinforcing
member of FIG. 180.
[0110] FIG. 183 is a side view of an RF aortic punch.
[0111] FIGS. 184 and 185 illustrate plan views of directive
resistive heating and ohmic tissue heating systems, respectively,
for operating the RF aortic punch of FIG. 183.
[0112] FIG. 186 is a side view of a fixed length arteriotomy
device.
[0113] FIGS. 187-189 illustrate the steps in fabricating a
side-to-side vascular coupler.
[0114] FIGS. 190-192 illustrate adjacent and alternating petal
configurations of a side-to-side vascular coupler.
[0115] FIGS. 193-197 illustrate the steps of implanting the
side-to-side vascular coupler of FIGS. 190-192.
[0116] FIGS. 198-202 illustrate the steps in compressing a slotted
vascular coupler having partial adherence between the stem and the
overmold or coating.
[0117] FIG. 203 is a side view of a vascular coupler having suture
members for attaching the vascular coupler to a vessel.
[0118] FIGS. 204 and 205 are side and perspective views of an
aortic punch.
[0119] FIGS. 206 and 207 are perspective bottom and top views of an
occluder having an occluding ball and occluding stop.
[0120] FIG. 208 is a side view of a hand-held occluder that can be
used to occlude an opening in a vessel prior to placing a vascular
coupler.
DETAILED DESCRIPTION
[0121] Referring to FIG. 1, a bypass vessel or graft 100 is
connected at a proximal end 105 to the aorta 110 and at a distal
end 115 to a coronary artery 120. At least one of the connections
between the graft 100 and the aorta 110 and between the graft and
the coronary artery 120 is formed using a vascular coupler or
connector 123, as described in greater detail below. The vascular
couplers described herein enable physicians to perform clampless
bypass surgery and can function as sutureless anastomosis couplers.
Novel features of some of the vascular couplers described herein
include the overmolded stem/strain relief, ridge, and hemostatic
gasket that are created using a compliant/elastic/flexible
material. Overmolding these components is advantageous because they
are not simply a coating or covering of an existing structure but
instead are an integral component.
[0122] In general, the overmolded vascular coupler can be
fabricated using multiple, independent petals around which an
over-molded component is fabricated. In general, a multi element or
multi petal vascular coupler is over molded with a compliant
material, allows for radial expansion and contraction, and
functions similarly to a traditional sutured anastomosis because
this design allows for pulsatile, compliant, radial motion. To vary
or tailor compliance, multiple slots, groves, hinges, reduced wall
thickness areas may be formed in between the petal elements, and
may increase the radial flexibility/compliance. Moreover, this
general design provides for radial compression without a slit
through the stem wall, and without the use of a hinge. This design
also advantageously provides overlapping vessel-contacting petals
because that feature is generally only possible when fabricating
the vascular coupler from multiple, independent
petals/elements--this is not possible for couplers that are
fabricated from a single tube. This design also advantageously
allows for the end of the petals extending outwardly from the stem
to be larger (i.e., widen) as it extends away from the stem. Using
multiple independent petals also allows for complete vessel contact
by having overlapping petals at the site of the aortic punch or
core site, and the arteriotomy for the coronary anastomosis. These
features and advantages are discussed in more detail below.
[0123] In general, the over-molded multiple element versions of the
vascular coupler is applicable as an aorta vascular coupler,
coronary vascular coupler and peripheral vascular coupler. The
range of diameters for the vascular couplers can be, for example,
between approximately 1.0 mm and 4 mm (or larger for peripheral
versions), and can be angled at between approximately 20 and 90
degree angles, or other, and be round, oval or other desired
geometry.
[0124] Referring to FIGS. 2-5, a vascular coupler 125 includes a
stem 130, ridges 135, petals 140, a hemostatic gasket 143, and
securing members 145. The bypass vessel 100, such as an internal
mammary artery (IMA) or saphenous vein, extends from the stem 130
at a proximal end 150 of the coupler 125 and terminates within the
coupler at a distal end 155. The stem 130 includes strain relief
members 160 that extend proximally from the proximal end 150 of the
stem and provide strain relief to the vessel 100. Although only one
embodiment of the strain relief members is illustrated in these
figures, other strain relief configurations are applicable for use
with the coupler 125. For example, the strain relief may have a
straight, slotted, or sinusoidal edge to provide more of a
compliance transition area or region. Additionally, the wall
thickness of the strain relief may be reduced in the direction of
the proximal edge to increase flexibility.
[0125] The securing members 145 are generally U-shaped and include
an outer arm 170, an inner arm 175, and a connecting portion 180
that connects the outer arm to the inner arm. The outer arm 170
extends along the outer surface of the coupler 125, the connecting
portion 180 extends across the distal end 155 of the coupler, and
the inner arm 175 extends along and against the vessel 100 in the
inner lumen 165 of the coupler. The outer arm 170 and the inner arm
175 include one or more protrusions 185 that, when the arms are
compressed against the vessel 100 and the stem 130, provide
resistance to pulling the vessel out of the coupler 125. The
protrusions 185 can be of any configuration that provides
resistance to pulling the vessel out of the coupler. For example,
the protrusions can be in the form of a roughened surface or tissue
penetrating pins. The securing members 145 can be made of, for
example, a biocompatible superelastic, shape memory, or deformable
metal or plastic that can be moved from an open position to a
closed position. In the open position, the stem 130 and the vessel
100 can be inserted into a gap formed between the outer arm 170 and
the inner arm 175. In the closed position, the gap is reduced to
compress or hold the position of the vessel 100 relative to the
stem 130. Thus, if the securing members 145 are made of a
superelastic material, such as Nitinol, the securing members are
formed to be in the closed position and the gap formed by exerting
a opening force to the arms 170, 175. When that force is removed,
the gap is reduced as the arms move towards each other. Similarly,
if the securing members are made of a deformable material, a force
is applied to close the gap by moving the arms towards each
other.
[0126] The stem 130 and hemostatic gasket 143 are made of a
biocompatible elastic/compliant/flexible material, including ePTFE,
silicone, or polyurethane. The stem 130 includes the ridges 135,
which extend outwardly from the circumference of the stem
circumferentially adjacent to the petals 140. Each petal 140
includes a first arm 190 that is connected to a second arm 195
through a transition region 200. In this embodiment, the second arm
has a generally T-shape, although many other shapes also are
suitable if they adequately compress the receiving vessel (i.e.,
the vessel being bypassed) between the ridges 135 and the petals
140. The petals 140 extend from the distal end 155 of the stem 130,
the first arm 190 being embedded within the stem 130, the
transition region 200 extending from the stem 130 and the second
arm generally parallel to the ridges 135. The petals 140 are made
from a superelastic/shape memory material, such as Nitinol, a
nickel-titanium alloy. In this manner, the petals 140 can be moved
from a compressed position to a released position. FIGS. 2-5
illustrate the petals 140 in the released position. In the
compressed position, the petals 140 are oriented approximately
90.degree. such that they are generally collinear with the stem
130. As explained in greater detail below, by placing the petals
140 in the compressed position using a compressing force, the
petals can be inserted into an opening in the receiving vessel and
then the compressing force removed such that the petals return to
the released position, thereby trapping the vessel wall between the
ridges 135 and the petals 140. The petals are illustrated as being
sheet-like. However, other starting materials can be used, such as
a wire. One benefit of using a wire to fabricate the petals is a
reduction in the amount of foreign material that is implanted
and/or in the blood stream. The greater the surface area of the
petals, the longer it takes to endothelialize that surface. As
such, wire petals can be fabricated to have less than 0.020 inches
that need to be endothelialized, providing benefits to the
patient.
[0127] Referring to FIG. 6, the vascular coupler 125 can be
fabricated with an optional enlarged hemostatic gasket 205
positioned around the circumference of the hemostatic gasket 143
within a space 210 defined between the ridges 135 and the petals
140. The space 210 receives the vessel wall of the vessel in which
the coupler is implanted. The enlarged hemostatic gasket 205
provides additional sealing function in the event that there is
play or looseness in the interface between the opening in the
receiving vessel and the stem after the coupler is implanted. The
compliance of the gasket 205 is atraumatic to the arteriotomy
edges, provides sealing, and mechanical securement.
[0128] The coupler 125 can be fabricated using many methods known
to those of skill in the art. One representative method is
described below. In these methods, the petals and securing members
may be produced at the same time, either as individual separate
components or connected together. Initially, the desired pattern of
the petals and securing members is chemically etched onto a flat
sheet of superelastic/shape memory material, such as Nitinol. The
etching produces the coupler components. The resulting cross
section geometry of the parts may be round, oval, square, square
with rounded corners, or any other suitable shape. The etched
pattern then is bent and/or annealed into a specific shape using a
suitable fixture. The ends of the etched pattern then are joined
together by using one or more of several methods including, for
example, (1) inserting an end that includes a tab into a slot,
groove, or hole; and (2) soldering, welding, adhesively bonding, or
applying any other suitable joining process to the ends.
Alternatively, the section or sections may not be joined, or
otherwise attached together. The desired shape is imparted by the
bending and/or annealing described above. The design that does not
incorporate joining may allow additional flexibility at one or more
regions of the coupler.
[0129] In the method described above, there are additional optional
steps. For example, the etched pattern can be chemically polished
or electropolished. In particular, the elements that will come in
contact with blood and/or tissue may be polished. If desired or
necessary, the etched pattern may be bent and/or annealed using the
fixture one or more additional times to better form the elements'
shapes and/or to impart a sharp curve or bend that would not be
possible to impart with single annealing. Similarly, an etching or
grinding process may be used to reduce the thickness of the sheet
or other starting material, which additionally removes any unwanted
material.
[0130] Once the parts are etched, shaped, electropolished, and
joined, as each of these steps are necessary, the etched and formed
pattern then is placed into a mold and overmolded to produce the
ridges 135, stem 130, strain relief 150, and hemostatic gasket 205.
The coupler 125 next may be coated (e.g., dipped, sprayed,
vacuum-assisted impregnation, or other suitable process or method)
with a therapeutic or pharmacologic compound or material. The
hemostatic gasket may be fabricated in a second, subsequent
overmolding step using the same or a different material.
[0131] Of course, other methods and steps for fabricating the
coupler can be substituted for the above process. For example,
alternative machining methods to the chemical etching steps include
but are not limited to photo-etching, electron discharge machining
(EDM), laser cutting, grinding, traditional cutting. Similarly,
alternative substrates or starting materials that can be used
instead of the flat sheet include but are not limited to wire, rod,
hoop, tube (e.g., having a round, square, or other geometry), coil,
strip, or band. Instead of the overmold fabrication method of the
stem, strain relief, and ridge, other methods may be used,
including but are not limited to extrusion, casting, molding
(injection or other), sintering, dip coating, spraying, weaving,
laminating, stereo lithography (i.e., 3-D layering).
[0132] The vascular couplers described above (i.e., vascular
coupler 125) and herein may be made from a variety of materials.
For example, the petals may be made of a superelastic or shape
memory metal or plastic that can be deformed during deployment to
have the cross-sectional profile of the vascular coupler reduced.
One example of a suitable superelastic/shape memory metal is
Nitinol, a nickel and titanium alloy. Other suitable similar
materials include other superelastic metal alloys, including spring
stainless steel 17-7 PH, other spring metal alloys such as
Elgiloy.TM., Inconel.TM., platinum-tungsten alloy, and superelastic
polymers. The securing members may be made from the same or
different materials as the petals.
[0133] The overmolded stem, ridges, and hemostatic gasket may be
partially or completely fabricated from many different types of
synthetic biocompatible materials, including Silicone,
Polyurethane, Polytetrafluoroethylene (PTFE), Expanded
polytetrafluoroethylene (ePTFE), Polyester, Dacron.TM., Mylar.TM.,
Polyethylene, PET (Polyethylene terephthalate), Polyamide,
Polyamide, PVC, Kevlar.TM. (polyaramid), polyetheretherketone
(PEEK), polypropylene, Polyisoprene, polyolefin, or a composite of
these or other suitable materials. Some polymer materials could be
irradiated in a desired geometry, for the shape to be "set" into
that position. A similar process using heat instead of radiation
could be used where the thermoplastic polymer is annealed (and
cooled) into a particular shape and geometry.
[0134] The stem, ridges, and hemostatic gasket also can be
partially or completely made from many different types of
biodegradable/bioabsorbable materials, including modified starches,
gelatins, cellulose, collagen, fibrin, fibrinogen, elastin or other
connective proteins or natural materials, polymers or copolymers
such as polylactide [poly-L-lactide (PLLA), poly-D-lactide (PDLA)],
polyglycolide, polydioxanone, polycaprolactone, polygluconate,
polylactic acid (PLA), polylactic acid-polyethylene oxide
copolymers, poly(hydroxybutyrate), polyanhydride, polyphosphoester,
poly(amino acids), poly(alpha-hydroxy acid) or related copolymers
of these materials, as well as composites and combinations thereof
and combinations of other biodegradable/bioabsorbable
materials.
[0135] Additionally, the stem, ridges, and hemostatic gasket can be
partially or completely fabricated from materials that swell or
expand when they are exposed to a fluid (such as blood, another
body fluid, or an infused fluid). These materials include
hydrophilic gels (hydrogels), foams, gelatins, regenerated
cellulose, polyethylene vinyl acetate (PEVA), as well as composites
and combinations thereof and combinations of other biocompatible
swellable or expandable materials.
[0136] The stem, securing members, hemostatic gasket, and petals
can be configured to have increased biocompatibility and/or blood
compatibility, such as by having a textured surface that promotes
endothelial cell growth and adhesion.
[0137] Referring to FIGS. 7a-7c, a deployment tool 220 can be used
to deploy the vascular coupler 125 into an opening 265 in a vessel
120. As briefly described above, the petals 140 can be moved into a
constrained position in which they extend distally from the stem
130. In such a configuration, the profile of the coupler 125 is
reduced, which eases the implantation of the coupler through the
opening 265 in a blood vessel and reduces the necessary diameter of
the opening 265 into the vessel 120. The deployment tool 220
includes a handle 225, a first rod 230, a second rod 235, and a
plate 240. The first rod 230 is pivotally mounted to the handle
225, the second rod 235 is mounted to the first rod and extends
through a channel 245 in the handle 225. The second rod 235
includes a pushing end 250 that extend from the channel 245 above
the plate 240. The plate 240 includes an opening 255 that is
connected to a slot 260. The opening 255 is configured to receive
the vascular coupler 125 (FIG. 7c) and the second rod 235 is
configured to be advanced in the channel 245 to push the coupler
from the opening 255 through the slot 260 to release the deployment
tool 220 from the coupler. The petals 140 of coupler 125, or the
analogous petals of a different coupler, as illustrated in FIG. 7c,
are constrained in the distally extending position by opening 255.
The notches in the plate 240 function as hinges to release the
coupler from the opening 255. Removing the coupler from the opening
deforms the plate 240. As such, the deployment tool 220 is likely
to be a single use device. The notched deployment tool 220 can be
fabricated without the first rod and second rod used to push the
coupler from the tool.
[0138] Referring also to FIG. 7d, after placing the extended petals
140 through the opening 265, the second rod 235 is advanced to push
the coupler from the opening 255 and through the slot 260. The
petals 140 then will be released from the constraining force after
the coupler is dislodged from the slot. When the constraining force
is removed, the petals will expand outwardly and trap the vessel
wall 270 in the space 210 between the ridges 135 and the petals
140. If, for example, the opening 265 is formed too large and there
is play between the opening and the stem 130, the hemostatic gasket
205 will reduce the likelihood that blood will leak from the vessel
120 through the opening.
[0139] Referring to FIGS. 8a and 8b, similar to the vascular
coupler 125 being deployed in a coronary artery, a vascular coupler
272 can be deployed into an aorta 273 using the deployment tool 220
and the second rod 235 advanced to deploy the coupler 272 into
position.
[0140] Referring to FIGS. 9a and 9b, a deployment tool 275 can be
configured similarly to the deployment tool 220 except that the
rods used to deploy the coupler 272 are not present. Using this
deployment tool 275, the coupler is removed by the surgeon who
relies on one or more weakened sections 277 in the plate 240 to
cause the slot 260 to enlarge in width by holding the coupler in
position while pulling back on the deployment tool 275. One of
several advantages of the deployment tool 275 is its simplicity of
manufacture and use. This leads to a potential low cost and single
use status.
[0141] Referring to FIGS. 10a-10c, a related tool that has some
similarities to the deployment tools is a vessel loading tool 285.
The vessel loading tool 285 includes a handle 287 and a retaining
member 289. The retaining member 289 extends from the distal end of
the handle 287 and includes a partially or completely
circumferential wall 291 that defines a lumen 292 and has a leading
edge 293 and a trailing edge 295. The vessel 100 is mounted to the
retaining member 289 by passing it through the lumen 292 and then
everting the distal end of the vessel around the leading edge 293
of the retaining member. The vessel 100 can be everted and pulled
back over the retaining member to the extent that it extends beyond
the trailing edge 295. After the vessel 100 is mounted to the
retaining member 289, the physician uses the handle 287 to advance
the retaining member and vessel into the vascular coupler 125
between the securing members 145 and the stem 130. The securing
members 145 then are closed down upon the vessel 100 and the vessel
loading tool 285 is withdrawn, leaving the vessel in place within
the vascular coupler 125.
[0142] Of course, numerous variations of the vascular coupler 125
are within the scope of this patent. For example, referring to
FIGS. 11-14, a vascular coupler 300 includes the stem 130, the
petals 140, the securing members 145, and a ridge 305. In contrast
to the vascular coupler 125, the vascular coupler 300 has a single
ridge 305 and embedded securing members 145. The embedded securing
members 145 are overmolded when the petals 140 are overmolded such
that the outer arms 170 are embedded within the stem 130, although
the inner arms 175 extend from either the distal end 155 of the
stem or the inner lumen 165 of the coupler. This reduces the
complexity of the procedure for the physician because the securing
members 145 will not accidentally be dropped when mounting the
graft 100 to the coupler 300. FIG. 12 illustrates the securing
members 145 in the position with a large gap and the graft 100
positioned within the coupler prior to securement. FIG. 13, in
contrast, illustrates the securing members 145 deformed or released
into the position with the small gap and the graft 100 therefore
securely positioned within the coupler. FIG. 14 illustrates the
coupler 300 mounted to the vessel 120 such that the single ridge
305 is secured against the outer surface of the vessel. Although
FIGS. 11-14 show the coupler without the hemostatic gasket 205, the
gasket optionally can be included on this coupler.
[0143] Because the securing members 145 are integrally mounted to
the coupler, there is no need to have multiple ridges 135 that are
spaced apart around the circumference of the coupler as are
necessary to place the securing members 145 to the coupler.
Instead, a single ridge 305 can be overmolded and the single ridge
configured to encircle the entire circumference of the coupler.
However, the single ridge 305 can be configured to encircle less
than the entire circumference of the coupler such that the coupler
can be curled within itself, as described in greater detail
below.
[0144] Referring to FIG. 15, a vascular coupler 320 includes the
stem 130, petals 140, embedded securing members 145, a single ridge
325, and a hemostatic gasket 205. The vascular coupler 320 is
similar to the vascular coupler 300, except that the coupler 320
additionally includes the hemostatic gasket 205 and a reinforcing
ring 330. The reinforcing ring is an elastic ring made of, for
example, metal or plastic, that provides reinforcing
circumferential hoop strength to the coupler. The reinforcing ring
330 can encircle the entire circumference as a closed ring, the
entire circumference as a ring with two adjacent or non-joined
ends, or as a ring that leaves a gap. A pair of adjacent or
non-joined ends allows some elastic expansion without providing any
restraining force to the coupler ballooning open. Although the
reinforcing ring is illustrated as being a rod having a round
cross-sectional shape, actual circumferential shape of the ring can
be varied greatly, as can the basic material (i.e., a rod). For
example, a sinusoidal, rectangular-shaped band or sheet can be used
in place of the rod.
[0145] Referring to FIGS. 16-18, the petals 140 and the securing
members 145 can be fabricated as a single piece by etching or
otherwise machining a single sheet 335 of starting material. As
illustrated in FIG. 16, the petals 140 and are securing members 145
are etched such that they extend from a common edge 340. For
example, the petals 140 are etched with the first arm 190 and the
second arm 195 in a common plane. Openings or grooves 345 also can
be etched in the first arms 190 to provide increased bonding
strength during overmolding. The securing members 145 likewise are
etched with the outer arm 170, the inner arm 175, and the
connecting portion 180 in a common plane. As illustrated in FIG.
17, however, after bending the securing members' inner arms 175
extend inward and the petals' second arms 195 extend outward. Then
as illustrated in FIG. 18, by bending the common edge 340 to form a
partially or completely closed loop, the petals 140 extend outward
and the securing members extend inward. This part 335 then can be
overmolded to form a coupler with embedded securing members.
[0146] Referring to FIGS. 19-21, a vascular coupler 350 includes a
stem 130, a ridge 355, a petal 360, and a strain relief 365. A
lumen 370 passes through the strain relief 365 and the stem 130.
The strain relief 365 is a coiled (e.g., coiled wire or spring)
that is embedded within the stem 130 and extends from a proximal
end 375 of the stem. The petal 360 is an extension of the strain
relief and extends from a distal end 380 of the stem. As evident
from FIGS. 19-21, the stain relief 365 and the petal 360 are of a
different diameter, and can be of a different pitch as well. The
petal 360 includes a curled distal end 385 that is configured to
prevent puncturing of the receiving vessel 120 when the coupler 350
is implanted. The coupler 350 is fabricated, for example, by
overmolding. The strain relief 365 and petal 360 are formed
initially, placed in a mold, and the stem 130 and ridge 355 formed
by overmolding with a compliant material, as described above.
[0147] Although FIGS. 19-21 do not show the securing members 145
and the bypass vessel 100, they are incorporated in any manner
described herein. For example, the outer arms 170 of the securing
members can be embedded within the stem and then the inner arms 175
extend into the lumen 370. Alternatively, the securing members 145
can be loose, the ridge 355 replaced with multiple, separated
ridges, and the securing members positioned between the ridges and
used to clip the vessel 100 to the coupler. The strain relief 365
therefore surrounds the outer surface of the vessel 100. The strain
relief 365 can be extended well beyond the coupler 350 and used to
provide anti-kink resistance to the bypass vessel 100.
[0148] The coupler 350 is inserted into an opening in a blood
vessel using one of a number of methods. For example, the coupler
can be inserted using in a push-pull method. In this method, the
petal is pressed against the opening in the vessel, which causes
the petal to be bent in the direction of the ridge and thereby
reduce the petal's diameter. The petal then slips through the
opening and the physician pulls back on the coupler, if necessary,
to seat it within vessel opening. Alternatively, the petal can be
pushed in at an angle such that part of the petal is within the
opening and then the rest of the petal pushed in. In another
alternative, the petal can be screwed in by putting part of the
petal in the opening and then rotating it to place the rest of it
within the opening.
[0149] Referring to FIGS. 22-24, a vascular coupler 390 includes
the stem 130, the ridge 355, the strain relief 365, and a pair of
petals 395. The primary difference between the coupler 350 and the
coupler 390 is the substitution of a pair of petals 395 for the
single petal 360.
[0150] Referring to FIG. 25, a vascular coupler 400 includes four
petals 405, but otherwise is similar to the vascular couplers 350
and 390. The figures indicate that one or more petals can be used
on the couplers.
[0151] Referring to FIGS. 26-28, a vascular coupler 420 includes
the stem 130, the ridge 305, and petals 425. The petals 425 are
formed from a wire or rod and bent to have a pair of outwardly
flared arms 430, a pair of parallel intermediate sections 435, and
a generally U-shaped segment 440 connecting the parallel
intermediate sections 435. The U-shaped segment 440 is embedded in
the overmolded stem. The wire or rod petals advantageously reduce
the amount of foreign material in the blood stream. Although FIGS.
26-28 illustrate an overmolded system in which the petals are
overmolded when the stem is formed. However, the overmolded stem
can be fabricated initially and channels left in the stem to
receive the petals. This technique can be used for all of the
overmolded couplers described herein. The securing members can
likewise be fabricated.
[0152] Referring to FIG. 29, a vascular coupler 450 includes wire
or rod petals 455 that are generally T-shaped. The wire or rod
forms the T-shape with an open region 460 between the wire or rod.
Referring to FIGS. 30 and 31, a vascular coupler 470 includes
U-shaped wire or rod petals 475. The wire or rod forms the U-shape
with an open region 480 between the wire or rod. Referring to FIG.
32, a vascular coupler 480 includes wire or rod petals 480, each
petal includes a single arm 485 that terminates in a coiled,
atraumatic tip 490.
[0153] Although using wire or rod petals to minimize the amount of
foreign material in the blood provides advantages, the petals may
be fabricated from sheets or plates, as described above. For
example, referring to FIG. 33, a vascular coupler 500 includes
V-shaped petals 505 that are formed from a sheet or plate by, for
example, etching. Each petal 505 includes a pair of arms 510 that
are connected at a base 515. The base extends into the overmolded
stem. Referring to FIG. 34, a coupler 520 includes petals 525 that
are formed from a sheet or plate by, for example, etching. Each
petal 525 includes a pair of arms 530 that are connected at a base
535 and at an end 540 opposite the base. The connections result in
an open region 545 between the arms 530. This configuration reduces
the amount of material in the blood stream and in contact with
tissue while yet providing adequate pull-out resistance. Referring
to FIG. 35, a coupler 550 includes petals 555 formed from sheets or
plates, as described above. The petals 555 are generally T-shaped
and include a pair of perpendicular arms 560 and 565 and an opening
570. The arm 565 extends from a base 575 that extends into the
overmolded ridge.
[0154] Referring to FIG. 36, a vascular coupler 590 includes
partially Z-shaped petals 595. The Z-shaped petals 595 include a
pair of arms 600, 605 connected at a joint 610. The arm 600 extends
at an opposite end from the joint 610 from a base arm 615. The base
arm 615 extends from the overmolded stem. Although the petals 595
have more material within the lumen than other versions described
herein, they advantageously provide perceived and/or actual
increases in the attachment of the coupler 590 to the vessel
120.
[0155] Referring to FIGS. 37 and 38, a vascular coupler 625
includes overlapping petals 630. Each petal 630 includes a base 635
that extends into the overmolded stem, a first arm 640 that extends
from the base to a second arm 645. The second arm 645 includes a
tip 650 that overlaps an adjacent first arm 640.
[0156] The above vascular couplers are illustrated showing a
90.degree. angle formed between the stem and the overmolded ridge.
However, other angles can be formed, based in part on the location
in the body in which the coupler is to be placed. For example,
referring to FIGS. 39-42, a vascular coupler 675 includes a stem
680, a ridge 685, petals 690, a hemostatic gasket 695, and securing
members 700. The axis of the stem 680 forms an angle A with the
plane formed by the ridge 685. The angle A is 90.degree. in the
versions illustrated above, but is shown in FIGS. 39-42 at an angle
of approximately 45.degree.. Suitable angles range between
approximately 15.degree. and 75.degree. and, more particularly,
between approximately 30.degree. and 60.degree.. For example, the
aorta (proximal) can have an angle of approximately 45.degree. and
the coronary (distal) can have an angle of approximately
30.degree.. Studies indicate that these angles are useful for
preventing kinking. As illustrated in FIG. 42, the petals 690
include a first arm 705, a second arm 710, and a connecting portion
715. The first arm 705 is embedded within the stem 680 and the
ridge 685. Extending the first arm 705 into the ridge 685 provide
additional elastic strength to the ridge 685. An additional
difference between the vascular couplers above and the vascular
coupler 675 is the oval cross-sectional profile of the lumen 720 of
the stem 680 and the opening into the vessel 120.
[0157] Referring to FIGS. 43-45, a vascular coupler 730 includes a
stem 735, a ridge 740, circumferential petals 745, longitudinal
petals 750, a hemostatic gasket 755, and securing members 760. The
vascular coupler 730 is particularly configured to conform to the
geometry of the vessel 120 in which the coupler is implanted. For
example, the ridge 740 is curved to match the circumference of the
vessel 120. As illustrated in FIG. 44, the ridge 740 includes a
pair of circumferential regions 765 that encircle a portion of the
circumference of the vessel. Similarly, the circumferential petals
745 are configured to conform to the inner circumference of vessel
120 by having a curved shape. The longitudinal petals 750 extend
proximally and distally of the coupler along the longitudinal axis
of the vessel 120. This arrangement of the petals 745, 750
contributes to increased pullout resistance of the coupler from the
vessel. Similar to the vascular coupler 675, the stem 735 is at an
angle relative to the ridge 740 that is less than 90.degree..
[0158] Referring to FIGS. 46-49, a vascular coupler 775 includes a
stem 780, a ridge 785, a reinforcing ring 790, a hemostatic gasket
795, and mounting clips 800. The ridge includes a large thickness
lip 805 and a thinner connecting region 810 extending between the
lip 805 and the stem 780. The primary difference between the
coupler 775 and the couplers above is that the mounting clips 800
are used in place of the petals in this configuration. The mounting
clips 800 pass through the vessel 120 and the ridge 785, and more
specifically, through the thinner region 810. The mounting clips
800 can be made, for example, of a traditional suture material or a
superelastic metal, such as Nitinol. One commercially available
suitable mounting clip is that marketed by Coalescent Corporation
of Sunnyvale, Calif. The mounting clips 800 are used to attach the
vascular coupler 775 to the vessel 120 in manners known to those of
skill in the art. The reinforcing ring 790 provides strength to the
ridge 785 and prevents, if necessary, pull-though of the mounting
clips 800 through the ridge when the mounting clips are
tightened.
[0159] Referring to FIGS. 50-55, a valved coupler 820 includes a
base 825 and a fitting 830 that is configured to receive a bypass
vessel 100 and be inserted into the base. The base 825 includes a
bi-leaflet valve 835 mounted to the base within a lumen 840 of the
base. The valve 835 is configured such that inserting the fitting
830 into the lumen 840 moves the leaflets 843 to an open position
such that blood can flow from the vessel 100 into a vessel 120
(FIGS. 53-55). Similarly, the valve 835 is configured such that
removing the fitting 830 causes the leaflets 843 to return to a
closed position (FIGS. 50-52). In the open position, a first
section 845 of the fitting 830 physically displaces the leaflets
843 such that they are pressed against or adjacent to an inner wall
850 of the base. The fitting 830 is retained in the base 825 by one
or more tabs 855 that slide into and twist through one or more
channels 860 that are formed in the wall 850 of the base. Such
twist lock methods are well known in the art. Similarly, the bypass
vessel 100 can be attached to the fitting 830 using any of the
methods that are well-known in the art. For example, the vessel 100
can be placed over a proximal end 865 of the fitting 830 and
attached to the fitting using, for example, adhesion, compression,
or other suitable attachment means. One advantage of this
configuration is the ability to insert the base 825 within a vessel
and subsequently connect and remove the fitting 830 when
necessary.
[0160] Referring also to FIGS. 56 and 57, the base 825 can be
configured to receive a closure cap 870 that, similarly to the
fitting 830, includes one or more tabs 875. In contrast to the
fitting 830, the closure cap 870 has a reduced length first section
880, relative to the first section 845 of the fitting 830. In this
manner, when the tabs 875 are inserted within the channels 860, the
valve leaflets 843 are not displaced into the open position.
[0161] Referring to FIGS. 58-60, an extension of the valved coupler
820 is a stand-alone reinforcement 900 that is comprised of many of
the features above including a ridge 905 and a reinforcing ring
910. The native pair of valve leaflets 915 are prevented from
separating by the ridge and ring preventing the diameter of the
valve from opening up too much. Multiple sutures or mounting clips,
e.g., mounting clips 800, are used to secure the reinforcement 900
to the tissue. The reinforcing ring 910 passes through the inside
of the ridge 905 along all or part of the circumference of the
ring. The reinforcement 900 advantageously can be easily implanted
in tissue 920 through a minimally invasive surgical procedure.
[0162] The reinforcing ring can be a Nitinol hoop or band and may
form a complete circumference or a partially circumference (e.g.,
complete or incomplete cross sectional circle--incomplete circle
would allow for normal radial vessel expansion and contraction,
maintain the same, or smaller diameter than a complete circle,
depending on the annealed geometry and diameter). While Nitinol has
many unique features and benefits, other materials may also be used
for the reinforcing ring. The ring may have a square, rectangular,
round, oval, combination or other shape or geometry. The surface of
the metal or metal alloy, may be electropolished, or have a coating
to enable or assist the healing process. Bonding and securing to
tissue can be accomplished by sutures (traditional, Nitinol, or
other), adhesive, combination or other. The ring may be expanded
from its resting, annealed configuration, and attached to a
deployment tool. The ring may then be attached to tissue (such as a
valve annulus) and secured, using sutures, adhesive or a
combination. The deployment tool may then be removed, allowing the
ring to recover back to its resting, or as annealed configuration,
cinching, placating, bunching, or otherwise bringing the tissue(s)
together to resist increase in the valve annulus diameter, e.g.,
caused by chronic cardiac conditions.
[0163] A second configuration is similar to that above but further
includes an over molded jacket with a proximal strain relief in the
stem region. Holes, slots, reduced thickness areas in the wall,
combination or other may be used to guide and or enable the use of
sutures.
[0164] A third configuration that is similar to those above does
not include a stem region. This configuration resembles a circle
and may have a reinforcing band, ring or other.
[0165] A fourth configuration includes holes, slots, reduced
thickness areas, combination or other to guide, assist or enable
the use of sutures with the anastomotic coupler.
[0166] The valved coupler can provide a safe, effective, quick and
intuitive-to-use vascular coupler that incorporates a valve and
quick connect, quick disconnect features. The purpose of the valve,
when in its closed position, is to prevent, obstruct and or limit
fluid or air flow. Another purpose is to prevent or obstruct flow,
until a tube or other is inserted into the inner diameter of the
coupler, opening the valve and allowing flow. Once the tube or
other is removed, the valve would close. Alternatively, the coupler
may not contain a valve--a replaceable plug, cap or occluding piece
may be used when flow is not desired (in between treatments for
example). The cap (or plug) may also be used with the valved
coupler. When inserted, it may be shorter, and not be in contact
with the valve (and thus the opening), but close enough to provide
a reinforcement to the valve or valve assembly components.
[0167] Additional uses for the valved coupler include being used as
a permanent or temporary access port for cardiovascular,
gastrointestinal, neurological, reproductive, lymphatic,
respiratory or other applications. The valved coupler may be used
during therapeutic infusion, diagnostic monitoring or sampling,
blood flow rerouting to provide ventricular assist for congestive
heart failure (from femoral artery to another vessel, with or
without the assistance of a pump). The valved coupler can be
permanently closed by using a cap or other component or method.
Sealing may be accomplished by mechanical interference fit,
adhesive, combination or other. The coupler, with or without
modifications, may be used as a device and method to deploy, and or
secure (temporarily or permanently) medical devices, including, but
not limited to, such devices as a ventricular conduit (between
ventricle and coronary artery, or other) from companies including
Ventrica (Fremont, Calif.) and HeartStent (Minneapolis, Minn.), and
AV shunts from companies such as Vasca (Tewksbury, Mass.). The
valved coupler also can be used for therapeutic infusion,
diagnostic monitoring or sampling, and
[0168] reinforcement/replacement of cardiac valves. The valved
coupler also can be removed, and replaced with another device, such
as in redo procedures. The replacement device may be another valved
coupler, non-valved coupler, or an arteriotomy closure device.
[0169] The valved coupler can be of any diameter (e.g., from 1 mm
to 20 mm or larger), any angle (e.g., from 15 to 120 degrees), any
geometry (e.g., round, oval, square, combination, etc.), and have
any suitable stem length (e.g., from 2 mm to 20 mm or longer). In
addition, the ridge section may be a different geometry than the
stem (e.g., the stem may be round, while the ridge may be
oval).
[0170] The design of the valve can include a separate piece bonded
inside the inner diameter of coupler (i.e., using an adhesive,
solvent, heat, combination or other suitable process), a removable
valve assembly, an over-mold and valve fabricated as one piece with
the coupler petals, on the connection tube end the coupler piece
may utilize a removable/replaceable plug or cap rather than a
valve, or the valve may be designed to not completely close to
allow a restricted flow to pass through the coupler. The valve type
can be a duck bill, a flapper, a check valve, a dilating membrane,
or other suitable type and design. The valve can be located at any
location inside and or on the outside of the coupler. The preferred
location is inside the inner diameter of the stem. Moreover, one or
more valves may be used.
[0171] The engagement of the valved coupler with the connecting
tube (e.g., bypass graft or vessel) can be by using mating threads,
a push in/twist to lock, a tapered tube/friction fit, or an
expandable, complete or partial circumferential balloon (or other
expanding/engaging structure) on or near the end of the connecting
tube. The expandable structure may provide both a mechanical
connection, as well as a fluid tight seal between the OD of the
connecting tube end, and the ID of the valve structure.
[0172] The valve material may be made of the same or different
material from coupler or coupler over-mold component. The valve may
contain a reinforcing material, such as nitinol, to act as a hinge,
and or a reinforcing support. The hinge or support may be on the
inside, outside, in-between or combination of the valve structure.
The reinforcing hinge or support material may be flat, round,
combination or other.
[0173] Of course, the vascular couplers described above can be
implemented with numerous variations in the components. For
example, referring to FIGS. 61 and 62, a vascular coupler 940
includes multiple petals 945 that are oriented in the general
direction of the ridge 950. For example, the angle between the
petals 945 and the hemostatic gasket 955 can be approximately 45
degrees. In this configuration, there is increased binding of the
vessel 120 between the petals 945 and the ridge 950.
[0174] Referring to FIGS. 63-66, a vascular coupler 970 similar to
those described above differs by including a petal member 975 that
is fabricated from a single wire, rod or etched sheet having joined
ends, although it is not strictly necessary to join the ends. In
forming the petal member 975, the wire or rod is bent to form
petals 980 and ridge reinforcements 985. The petal member 975 may
have a pair of ends 990 that are separated (as illustrated) or
adhered together.
[0175] In another variation of the vascular couplers described
above, the securing members also can be varied in numerous manners.
For example, referring to FIGS. 67 and 68, a securing member 1000
includes a pair of parallel sections 1005 that are joined by a
U-shaped tissue contacting member 1010. The parallel sections 1005
are either embedded within the stem 130 or positioned on the outer
surface of the stem. The U-shaped tissue contacting member 1010
extends into and along the inner wall of the coupler to compress
the vessel 100 against the coupler. Similarly, referring to FIGS.
69 and 70, a securing member 1020 includes a pair of parallel
sections 1025 that are joined by an inverted V-shaped tissue
contacting member 1030. The parallel sections 1025 are either
embedded within the stem 130 or positioned on the outer surface of
the stem. The inverted V-shaped tissue contacting member 1030
extends into and along the inner wall of the coupler to compress
the vessel 100 against the coupler. Similarly, FIG. 71 illustrates
a securing member 1035 that includes a broad V-shaped tissue
contacting member 1040 that provides additional contact against the
vessel. Likewise, FIG. 72 illustrates a securing member 1045 that
includes a triangular shaped tissue contacting member 1050 that
provides additional contact against the vessel.
[0176] The securing members also can be configured to have a
J-shape. In this configuration, the shorted segment is positioned
below the ridge and then the longer segment extends unto the lumen
of the coupler to secure the vessel to the coupler. In this manner,
the ridge does need channels to receive the securing member.
[0177] The securing members can be further modified to increase the
retention strength for retaining the vessel 100 within a coupler by
including tissue penetrating members. For example, a securing
member 1060 includes a U-shaped member 1065 and a tissue
penetrating member 1066. The tissue penetrating member 1066 is
directed inwardly from a first arm 1067 in the direction of a
second arm 1068. Referring to FIG. 74, a securing member 1070 that
is similar to the securing member 1000 further includes tissue
penetrating members 1076 that are directed inwardly from an
inverted U-shaped first arm 1077 in the direction of second arms
1078. Referring to FIG. 75, a securing member 1080 that is similar
to the securing member 1020 further includes tissue penetrating
members 1086 that are directed inwardly from an inverted U-shaped
first arm 1087 in the direction of second arms 1088. Referring to
FIG. 76, a securing member 1090 that is similar to the securing
member 1035 further includes tissue penetrating members 1096 that
are directed inwardly from a broad V-shaped first arm 1097 in the
direction of second arms 1098. Referring to FIG. 77, a securing
member 1100 that is similar to the securing member 1045 further
includes tissue penetrating members 1106 that are directed inwardly
from a triangularly-shaped first arm 1107 in the direction of
second arms 1108. Referring to FIG. 78, a seacuring member 1110
that is similar to the securing member 1060 further includes angled
tissue penetrating members 1116 that are directed inwardly and
downwardly from a first arm 1117 in the direction of a second arm
1118.
[0178] Referring to FIG. 79-81, the petals can be configured as
longitudinal wires or rods that compress the vessel wall between
the petals and the ridge. Specifically, a vascular coupler 1150
includes an overmolded ridge 1153 in which a longitudinal petal
1155 is partially embedded. In particular, the longitudinal petal
1155 includes a longitudinal section 1160 that is oriented along
the axis of the vessel 120 in which the coupler 1150 is implanted.
The petal 1155 also includes a first circumferential section 1165
and a second circumferential section 1170. The circumferential
sections 1165, 1170 extend from the longitudinal section 1160 and
connect to parallel longitudinal sections 1175. An opposite petal
1155 is positioned on the opposite side of the coupler, separated
laterally for the first petal.
[0179] Another variation in the vascular couplers described above
is the use of a circumferential spring member. For example,
referring to FIGS. 82-84, a vascular coupler 1200 includes a stem
1205, a ridge 1210, a hemostatic gasket 1215, and a circumferential
spring member 1220. The circumferential spring member 1220 includes
petals 1225 that are separated by inverted U-shaped connectors
1230. The spring member 1220 provides radial reinforcement to the
stem 1205. In particular, the stem 1205 can be made of a weak,
compliant material and the spring member used to provide radial
strength to the coupler. The spring member provides radial
expansion and contraction similar to a sutured or native
anastomosis. The spring also provides a dynamic response to the
pulsatile forces in the circulatory system. The spring member can
be made through a number of techniques. For example, a sheet or a
superelastic/shape memory material, such as Nitinol, can be cut or
etched to have the pattern of the spring member. The etched or cut
sheet then can be annealed to the shape illustrated in FIGS. 82-84,
placed in a mold, and overmolded. The two edges of the sheet used
to form the spring member can be joined or left separated by a
slight gap 1235. The spring member can be fabricated from the same
material as the petals.
[0180] Referring to FIG. 85, a vascular coupler 1250 that is
similar to the vascular coupler 1200 includes a narrower spring
member 1255 that has reduced height, inverted U-shaped connectors
1260 connecting the petals 1265.
[0181] Referring to FIGS. 86 and 87, a vascular coupler 1275
includes a stem 1280, a ridge 1285, petals 1290, and a spring
member 1293. The spring member 1293 is formed, for example, by
etching a sheet of a superelastic/shape memory material and then
annealing the shape of the finished spring member 1293. As
illustrated, the spring member 1293 is separate from and unattached
to the petals 1290. The spring member 1293 and the petals 1290 are
formed within the stem 1280 by placing them in a mold and
overmolding them with the material used to form the stem. Although
the spring member 1293 is shown as having a generally sinusoidal
configuration, other configurations may be used in this embodiment.
The spring member provides a response to deflection that can be
modified by the material used, the geometry, width, thickness, etc.
The response can also be modified by the design of the spring
element. The spring member may also be useful as a radial
reinforcement for the overmolded coupler.
[0182] Referring to FIG. 88, the vascular couplers herein may be
modified to include a groove within the distal coupler wall to
receive an everted end of the bypass vessel 100. A vascular coupler
1300 includes a stem 1305, a ridge 1310, petals 1315, a reinforcing
ring 1320, and a hemostatic gasket 1325. The coupler 1300 includes
a groove 1330 that is coaxial with the longitudinal axis of the
coupler and is large enough to receive an everted end 1335 of the
vessel. A tool can be used to insert the everted end of the vessel
into the groove. The vessel may be additionally secured to the
coupler 1300 using the securing members described above, sutures,
adhesives, or a combination of these or other suitable
materials.
[0183] Although the above vascular couplers have generally been
formed to include an overmolded portion, vascular couplers of a
non-overmolded design also can be fabricated. For example,
referring to FIGS. 89-92, a vascular coupler 2125 includes a stem
2130 and petals 2135 that extend from a base 2140 of the stem. The
angle formed between the stem 2130 and the petals 2135 is between
approximately 80 degrees and 100 degrees and, more particularly,
approximately 90 degrees.
[0184] The stem 2130 includes an upper opening 2145, a channel 2150
passing between the upper opening 2145 and the base 2140, and a
lengthwise slot 2155 along the entire length of the stem and
passing from an outer surface of the stem to the channel 2150. As
described in more detail below, the lengthwise slot 2155 allows the
cross-sectional profile of the stem 2130 to be advantageously
reduced during loading of the bypass vessel on or in the coupler
and during implantation of the vascular coupler 2125. The stem 2130
also includes lengthwise slots 2160 that pass from the outer
surface of the stem to the channel 2150. However, the slots 2160 do
not extend the entire length of the stem 2130 but instead extend
only a portion of the length of the stem. The slots 2160 remove
material from the stem and thereby, when the coupler is implanted
in a vessel, reduce the amount of foreign material in contact with
tissue and blood.
[0185] The petals 2135 include an inner clip 2165 and an outer clip
2170, both of which extend from the base 2140. The petals 2135 are
used to attach the vascular coupler 2125 to a vessel, such as the
aorta. In particular, either of the inner clips 2165 or the outer
clips 2170 are inserted through an opening in the vessel and
allowed to expand to contact the inner lumen of the vessel. The
other of the inner clips 2165 and the outer clips 2170 are
positioned on the outside of the vessel. In this manner, the vessel
is positioned between the inner clips 2165 and the outer clips
2170.
[0186] The inner clip 2165 is in the form of a pair of lengthwise
edges 2175 that extend from the base 2140 at a first end of the
edges and a widthwise edge 2180 at a second, opposite end of the
edges. The lengthwise edges 2175 and the widthwise edge 2180 are
surrounded by a pair of lengthwise edges 2185 and a widthwise edge
2190 of the outer clip 2170. The various edges of the outer clip
2170 are separated from the various edges of the inner clip by a
channel 2193 that extends from the base 2140 to the widthwise edge
2185. Like the edges of the inner clip 2165, the lengthwise edges
2185 extend from the base 2140 at a first end of the edges and the
widthwise edge 2190 is at a second, opposite end of the edges and
connects the lengthwise edges 2185.
[0187] The various lengthwise and widthwise edges have upper
surfaces 2195 and lower surfaces 2200 that are connected by side
surfaces 2205. The joints between the side surfaces 2205 and the
upper surfaces 2195 and the lower surfaces 2200 may be smoothed,
angled, gradual, or sharp. In general, the joints will be
configured to limit the likelihood of damage to tissue or blood
when, as described below, the coupler 2125 is implanted in a
vessel.
[0188] The inner clip 2165 also includes an optional slit 2210
along its length. The slit 2210 can be wide or narrow and its shape
is not particularly limited. Moreover, the slit 2210 can have
widthwise slits (not shown) extending into the lengthwise edges
2175 and the widthwise edge 2180. Similarly, the lengthwise edges
2185 and the widthwise edge 2190 of the outer clip 2170 optionally
may have slits (not shown) extending from the slit 2210 into the
edges 2185 and 2190. These optional slits are used to provide more
flexibility to the clips 2165 and 2170 and, further, to reduce the
amount of foreign material in contact with the recipient's blood
and tissue. The inner clip 2165 and the outer clip 2170 are curved
to generally have a radius of curvature that matches the inside of
the vessel in which the coupler 2125 is to be implanted.
[0189] FIGS. 89-92 illustrate one configuration of the interface
2215 between the channel 2193 and the base 2140 of the stem 2130.
Although FIGS. 89-92 show the interface 2215 being of a constant
width, the interface can be wider than the width of the channel
2193 such that, when implanted, more tissue can be received within
the interface without pinching of the tissue between the outer clip
2170 and the inner clip 2165. For example, the interface 2215 can
be formed as a round opening.
[0190] Referring to FIGS. 93 and 94, a coupler 2230 includes a stem
2235 and petals 2240. Like the petals 2240, the stem 2235 includes
multiple inner clips 2245 and outer clips 2250. The petals 2240 are
used to mount a bypass vessel 2255, such as a synthetic or natural
vascular graft, to the coupler 2230. As illustrated in FIG. 94, one
of the inner clips 2245 or the outer clips 2250 are positioned on
the inside lumen of the bypass vessel 2255 and the other of the
inner clips 2245 and outer clips 2250 are positioned on the outside
of the lumen. Like the coupler 2125, the coupler 2230 has an angle
of between approximately 80 degrees and 100 degrees, and more
particularly, approximately 90 degrees.
[0191] As illustrated in FIG. 93, the coupler 2230 includes a wall
section 2260 in the stem 2235 between adjacent outer clips 2250.
The wall section 2260 extends to the petals 2240. The wall section
2260 can be removed to provide additional flexibility in the stem
2235 so that stem can be compressed to reduce its profile. However,
like the coupler 2125, the coupler 2230 includes a slit 2260
through the stem 2235 such that the profile of the stem can be
reduced when the coupler 2230 is being implanted. The slit 2260 can
be longitudinal or, as illustrated in FIGS. 93 and 94, formed as a
partial spiral around its circumference.
[0192] Referring to FIGS. 95-98, a coupler 2275 is similar to the
coupler 2125 with respect to the slots 2160 in the stem 2130 and
the inner clips 2165 and the outer clips 2170 in the petals 2135.
However, a primary difference between the coupler 2125 and the
coupler 2275 is the angle formed between the stem 2130 and the
petals 2135. In particular, whereas the angle formed within the
coupler 2125 is between approximately 80 degrees and 100 degrees,
the angle formed within the coupler 2275 is between approximately
35 degrees and 55 degrees, and more particularly, approximately 45
degrees. Like the coupler 2125, the coupler 2275 includes a slot
2155 that passes through the stem 2130 such that the profile of the
stem can be reduced. The slot 2155 is illustrated as being
positioned in the front region of the stem 2130 in FIG. 98 for
illustrative purposes. Similarly, the slot 2155 is illustrated as
being in the rear of the stem 2130 in FIGS. 97 and 98 for
illustrative purposes. Of course, it is intended that the slot 2155
can be positioned in any region of the stem 2130 in so much as the
profile of the stem can be reduced.
[0193] Referring to FIGS. 99-102, like the coupler 2275, a coupler
2300 includes the stem 2130 and the petals 2135. However, unlike
the coupler 2275, the coupler 2300 includes an extended section
2305 between the stem 2130 and the petals. The extended section
2305 is defined as a section that extends perpendicularly from the
petals 2135 and joins the stem 2135 such that the stem forms an
angle with the extended section. The angle between the stem and the
extended section 2305 is between approximately 35 degrees and 55
degrees, and more particularly, approximately 45 degrees. The
inventors believe that one advantage of the extended section 2305
is a reduced amount turbulence in the blood that flows into the
vascular coupler 2300. The coupler 2300 also includes the slot 2155
positioned in the front of the coupler. Of course, the slot 2155
can be formed in various other positions within the stem 2130 and
extended section 2305.
[0194] Referring to FIGS. 103-107, a deployment tool 2325 having
similarities to the deployment tools described above includes a
handle 2330 and a coupler holder 2335 positioned at the distal end
of the handle. The holder 2335 includes a plate 2340 through which
a channel 2345 passes. A slot 2350 passes from an exterior edge
2355 of the plate 2340 to the channel 2345. Any of the vascular
couplers described herein can be delivered and deployed using the
deployment tool 2325. In particular, as further illustrated in
FIGS. 108a and 108b, the vascular coupler 2125 is held within the
channel 2345 with the outer clips 2170 being compressed inwardly by
the inner edges of the channel 2345. The plate 2340 and the
external petals 2165 additionally can function as depth stops to
prevent the physician from inserting the vascular coupler too
deeply into the vessel by pressing against tissue surface.
[0195] To deploy the coupler 2125, the physician merely uses finger
pressure on the coupler to urge it through the slot 2350, which
removes the compressive force on the outer clips 2170 such that the
clips are released within the lumen of the vessel. The outer clips
2170 expand in the direction of the inner vessel wall. Because the
inner clips 2165 are in contact with the outer vessel wall, when
the outer clips 2170 expand against the inner vessel wall, the
vessel wall will be secured between the clips 2165 and 2170. In
this manner, the coupler 2125 and attached bypass graft (not shown)
will be securely attached to the vessel. Of course, whether
necessary or not, the physician can use stay sutures to
additionally ensure that the coupler 2125 will remain secured to
the vessel. It is expected that tissue will grow over and
encapsulate the outer clips 2170 over time within the vessel. As
such, the coupler 2125 will be even more securely attached to the
vessel and the clips 2170 will provide less of a thrombogenic
surface.
[0196] Of course, the vascular couplers described herein also can
be deployed using a hand held retractor, hemostat, tweezers, or
other similar device, including those described above.
[0197] Referring to FIGS. 109-116, like the vascular couplers
described above, and in particular the vascular coupler 2125, a
vascular coupler 2375 includes a stem 2130 and petals 2135.
However, unlike the vascular coupler 2125, the vascular coupler
2375 includes a V-shaped slot 2380 that runs the length of the stem
2130 and one or more V-shaped slots 2385 that run a part of the
length of the stem 2130. As noted, the slots 2380 and 2385 differ
in their length along the stem 2130. Otherwise, they are very
similar. For example, the slots 2380, 2385 can be formed by using a
laser to cut the slots; with the slot 2385 not being cut the entire
length of the stem whereas the slot 2380 is cut the entire length
of the stem. The V-shaped slots have a wider distal end 2390 and a
narrower proximal end 2393. This configuration of the slots 2380,
2385 allows the physician to even further reduce the profile of the
coupler in the region of the wider distal end 2390 of the slot.
[0198] Although the vascular coupler 2375 is illustrated as having
the slots 2380 and 2385, a vascular coupler can be formed with
either or both of the types of slots, and/or one or more of the
slots 2385. For example, a vascular coupler can be formed with four
slots 2385 such that the coupler can have its profile maximally
reduced at the interface between the petals and the stem.
Similarly, a vascular coupler can be formed with the slot 2380 and
no slots 2385, or the slot 2380 and, for example, one slot
2385.
[0199] In general, the vascular couplers 2125, 2230, 2275, 2300,
and 2325 are configured for deployment in a vessel, such as the
aorta. The angles between the stem and petals described above,
i.e., approximately 35 degrees to 55 degrees and approximately 80
degrees to 100 degrees, may be selected based on considerations,
such as fluid dynamics and the flow path of the blood between the
blood supplying vessel (e.g., the aorta) and the bypassed vessel
(e.g., a coronary artery). A vascular coupler placed in the
coronary artery has a generally smaller angle formed between the
stem and the petals of the coupler, although there may be some
overlap in the range of acceptable angles. For example, typically,
that angle is between approximately 20 degrees and 45 degrees, and
more particularly, approximately 30 degrees. Vascular couplers for
the coronary arteries are described next.
[0200] Referring to FIGS. 117-120, a vascular coupler 2400 includes
a stem 2405 and one or more longitudinal petals 2410 that extend
from a base 2415 of the stem in a longitudinal direction and one or
more lateral petals 2413 that extend from the base 2415 of the stem
in a lateral direction. Each longitudinal petal 2410 includes an
inner clip 2420 and an outer clip 2425. Like the vascular couplers
described above, one of the clips 2420 and 2425 is placed on the
inside of the blood vessel against the luminal wall and the other
of the clips 2420 and 2425 is placed on the outside of the blood
vessel against the vessel's outer wall. The outer clips 2425 are
configured such that they include a first section 2430 and a second
section 2435 that is generally perpendicular to the first section.
The length of the first section 2430 is selected to approximate the
thickness of the vessel wall through which it passes and against
the inner surface of which the second section 2435 is placed. The
angle formed between the stem 2405 and the longitudinal petals 2410
is between approximately 20 degrees and 45 degrees and, more
particularly, approximately 30 degrees.
[0201] The lateral petals 2413 each include an inner clip 2440 and
an outer clip 2445. The inner clip 2440 is configured to be placed
around the outer coronary artery wall of the coronary artery in
which the vascular coupler 2400 is implanted. In particular, the
inner clip 2440 may be configured to have a radius of curvature
that is similar to that of the outer diameter of the coronary
artery wall. Similarly, the outer clip 2445 is configured to be
placed inside the coronary artery and engage the wall of the lumen
of the coronary artery. As such, the outer clip 2445 has a radius
of curvature that approximates that of the inner diameter of the
coronary artery. The outer clips 2445 are configured such that they
include a first section 2450 and a second section 2455 that it is
at an angle to the first section 2450. The length of the first
section 2450 is selected to approximate the thickness of the vessel
wall through which it passes and against the inner surface of which
the second section 2455 is placed.
[0202] Differences between the lateral petals 2413 and the
longitudinal petals 2410 include the relative length and the
relative curvature of the outer clips. For example, the diameter or
cross-sectional profile of the stem is close to that of the vessel
(e.g., coronary artery) in which the coupler is inserted or
mounted. As such, there is more length of the artery to use the
petals 2410 to secure the coupler to the vessel than there is width
of the artery to use the petals 2413 to secure the coupler to the
vessel. Because of these constraints, there is no need to have a
radius of curvature of the outer clip 2425 along its length,
although there is a need to specify a radius of curvature of the
outer clip along its width. In contrast, because there is little
width of artery to use to secure the coupler to the vessel, there
is an increased need to fabricate the radius of curvature of the
outer clip 2445 such that it will engage a substantial amount of
the circumference of the inner luminal wall of the artery. The
vascular couplers 2125, 2230, 2275, 2300, and 2325 are designed for
insertion into the aorta, which has an inner diameter that is
significantly greater than that of the stem of the coupler, and, as
such, the petals that are aligned with the circumference will have
less of a need to be short or have a sharp radius of curvature
because the radius of curvature of the inner diameter of the vessel
is not as tight as in a coronary artery.
[0203] The stem 2405 of the vascular coupler 2400 is formed from
flattened or parallel walls 2460 and curved front and rear walls.
In contrast, the vascular couplers described above had curved
front, rear, and side walls, although they could easily be formed
with flattened side walls and curved front and rear walls. The flat
sides maximize cross-section area through the lumen of the vascular
coupler, with the limitation on the diameter of the coupler being
that of the opening into the artery in which the vascular coupler
is to be placed. To increase the cross-sectional area of the tube
through which blood flows, the inventors have increased the length
of the cross-section while leaving the width the same as
approximately the width of the opening in the artery. As described
below, when the vascular coupler 2400 is implanted in a coronary
artery, the vascular coupler advantageously forms a fit that
maximizes the cross-sectional area of the entry of the blood into
the coronary artery from the vascular coupler. This is believed to
advantageously promote hemodynamics and reduce damage to the blood
cells as well as the posterior vessel wall from the site of the
anastomosis. By having flattened, extended sides and longer side
clips, there is potentially better engagement and securement
because there is a greater amount of vessel in contact with the
coupler.
[0204] Referring to FIGS. 121-124, the vascular coupler 2400 is
shown in the process of being implanted (FIG. 121) or already
implanted in a coronary artery 2465 (FIGS. 122-124). To implant the
vascular coupler 2400, the artery is first prepared by, for
example, making a longitudinal cut 2470 along a part of the length
of the artery. The physician then places the outer clips 2425 and
2445 in a restrained position by using a restraining force provided
by either the physician's finger or a deployment tool, as described
above. In this position, the outer clips 2425 and 2445 are inserted
straight into the longitudinal cut 2470 (i.e., arteriotomy) and
then the physician removes the restraining force, which releases
the clips 2425 and 2445 such that they can return to their
unrestrained position. In the unrestrained position, the coronary
artery wall is positioned between the outer clips 2425 and inner
clips 2420, and between the outer clips 2445 and inner clips 2440.
As seen in FIG. 121, the length of the flattened side wall 2460 is
approximately the length of the slit 2470.
[0205] Referring to FIGS. 125-127, a vascular coupler 2500 is
similar to the vascular coupler 2125 with respect to the stem 2130
and the slot 2155 in the stem. However, the petals 2135 are less
rectangular in shape and instead are more V-shaped. Although each
petal 2135 includes an outer clip 2505 and an inner clip 2510 like
the vascular coupler 2125, the V-shaped configuration reduces the
amount of foreign body material within the vessel and in contact
with blood. In comparison to the vascular coupler 2400, the
vascular coupler 2500 has almost no space along the length of the
stem between the outer clip 2505 and the inner clip 2510 when the
vascular coupler is deployed. This characteristic can be
advantageously used to even more securely retain the vessel wall
between the outer clips and the inner clips. The vascular coupler
2500 is shown deployed within a large diameter vessel, such as the
aorta 2515, and providing a conduit for shuttling blood into a
bypass vessel 2520. Because the diameter of the aorta 2515 is much
larger than the diameter of the stem 2130, the opening or slit into
the aorta is unlikely to encompass a majority of the diameter of
the aorta. As such, the curvature of the outer clips 2505 is less
critical and can, in fact, be almost perpendicular to the stem
2130. Of course, depending upon the size of the aorta, or vessel in
which the vascular coupler is being deployed, the radius of
curvature of the petals can be easily modified to mate with the
inner surface of the vessel wall.
[0206] Referring to FIGS. 128-131, the vascular coupler 2500 is
shown having a compliant gasket 2530 mounted on the stem 2130
between the outer clips and the inner clips. In contrast to the
vascular coupler illustrated in FIG. 127, there are two
configurations of the outer clips in the vascular coupler of FIGS.
128-131. In particular, the vascular coupler 2500 includes
longitudinal outer clips 2532 and lateral outer clips 2533. The
longitudinal outer clips 2532 are generally planar to mate with the
generally planar surface of the length of the artery whereas the
lateral outer clips 2533 are generally curved to mate flush with
the generally curved surface of the width of the artery. However,
the longitudinal outer clips 2532 are curved across their width to
mate with the width of the tissue against which they are deployed.
The gasket 2530 advantageously provides a seal between the vascular
coupler 2500 and the longitudinal cut 2470. Generally, the gasket
2530 is compliant so that it will conform to the longitudinal cut
2470 and limit excessive blood flow between the longitudinal slit
and the gasket. The gasket 2530 can be advantageously configured to
cause a separation along the length of the stem 2130 that is
similar to the thickness of the vessel in which the vascular
coupler is deployed. Of course, the gasket 2530 can be as easily
configured such that there is very little separation along the
length of the stem 2130 so that there is more pressure on the
vessel wall between the inner clip 2510 and the outer clips 2532
and 2533.
[0207] The vascular couplers described above, and in particular the
vascular couplers illustrated in FIGS. 89-131, are individually
described with some of the features and without some of the
features. In general, any of the features described above can be
implemented on any of the vascular couplers. For example, the
longitudinal slot 2155 can be implemented in any and all of the
vascular couplers described above. Similarly, the longitudinal slot
2155 does not need to be implemented in any of the vascular
couplers.
[0208] Similarly, although deployment tools have been disclosed,
alternative versions of these deployment tools can be used. For
example, referring to FIG. 132, a deployment tool 2600 includes a
handle 2605, an arm 2610, a coupler holder 2615 positioned at the
distal end of the arm, and a pusher tube 2617. The coupler holder
2615 includes a plate 2620 through which a channel 2625 passes. A
slot 2630 passes from an exterior edge 2635 of the plate 2620 to
the channel 2625. The pusher tube 2617 is connected at a proximal
end 2640 to the handle 2605 or arm 2610 and passes through a
channel 2645 in the plate 2620. A distal end 2650 extends from the
channel 2645 and terminates in proximity to the channel 2625. The
pusher tube includes a middle section 2650 between the proximal end
2640 and the distal end 2650. The pusher tube is made of a flexible
material, such as a flexible metal or polymer, and by pressing the
middle section 2650 in the direction of the arm 2610, the distal
end 2650 extends further out of the channel 2645. Any of the
vascular couplers described herein can be delivered and deployed
using the deployment tool 2600. In particular, a vascular coupler
can be held within the channel 2625 with the outer clips being
compressed inwardly by the inner edges of the channel 2625.
[0209] To deploy a coupler that has been installed in the channel
2625, the physician merely applies pressure on the pusher tube 2617
to urge the coupler through the slot 2630, which removes the
compressive force on the outer clips such that the clips are
released within the lumen of the vessel. The outer clips expand in
the direction of the inner vessel wall. Because the inner clips are
in contact with the outer vessel wall, when the outer clips expand
against the inner vessel wall, the vessel wall will be secured
between the inner and outer clips.
[0210] The gasket (e.g., vascular coupler 2500) may be configured
to have circumferential grooves that improve acute hemostasis by
using the elasticity of the blood vessel to tightly mate within one
of the grooves. The grooves and the gasket may be coated with an
adhesive, therapeutic agent, and/or other beneficial material.
[0211] Referring to FIGS. 133-135, a vascular coupler 2700 is
implanted in a coronary artery 2705. To provide better support of
the vascular coupler 2700 against the coronary artery and the
epicardial surface 2710, the outer clips 2715 on the side of the
vessel are longer and wider than in the vascular couplers described
above. In particular, the side outer clips 2715 have a first
section 2720 and a second section 2725. The first section 2720
extends from the base of the stem and is selected to have a length
and form an angle with the base such that the first section extends
to approximately the epicardial surface 2710. The second section
2725 extends from the first section 2720 and is generally flush
with the epicardial surface, although it likely will compress the
epicardial surface. However, the coronary artery tissue is more
compressed by the interaction of the inner clip 2730 and the first
section 2720. The use of wider and/or longer outer clips 2715 on
the outside of the coronary artery and against the epicardial
tissue optionally may be used on any of the vascular coupler
described herein.
[0212] Referring to FIGS. 136-139, the vascular coupler 2500,
described above, is provided with a notched gasket 2740. The gasket
2740 includes longitudinal notches 2745 through which extend the
inner clips. The inner clips are shown as having two
configurations, longitudinal inner clips 2750 and lateral inner
clips 2755. The longitudinal inner clips 2750 have a generally
planar surface along its length to mate with the outer surface of
the artery. However, the longitudinal inner clips 2750 have a
radius of curvature across its width to mate with the radius of
curvature of the artery across its width. The lateral inner clips
2755 have a generally curved surface along its length to mate with
the outer circumferential surface of the artery. The notches 2745
remove an impediment to the complete deployment of the inner clips
2750 and 2755. The gasket 2740 also can include an upper ridge
between adjacent notches to function as an additional aid to
hemostasis. The gasket also can include circumferential grooves, as
described above.
[0213] Referring to FIGS. 140-143, another vascular coupler 2800
includes a stem 2805, multiple upper elements 2810, multiple lower
elements 2815, and a compliant gasket 2820. The upper elements 2810
are configured to be placed on the outer surface of a vessel and
the lower elements 2815 are configured to be placed on the inside
surface of a vessel. The compliant gasket, like the gaskets
described above, advantageously covers any potential blood leakage
between the recipient vessel and the coupler. The gasket also
provides a compliant material to improve acute hemostasis after the
coupler has been deployed. The gasket 2820 also can include
circumferential grooves to receive the edge of the arteriotomy. The
gasket 2820 also can include an adhesive, a therapeutic agent,
and/or another beneficial material or agent. The lower elements
2815 include slots 2830 that advantageously remove material from
blood and tissue contacting surfaces. In addition, if the slots are
made wide enough, a securing suture can be passed through the
vessel wall, into the and through the slot 2830, and used to ensure
that the vascular coupler 2800 is securely deployed within the
artery. The multiple elements 2810 and 2815 advantageously provide
attachment of the vascular coupler to the vessel around the
entirety of the arteriotomy.
[0214] Referring to FIGS. 144-147, a vascular coupler 2900 is
configured to connect a first tubular vessel 100 to an aperture in
a second tubular vessel 120. For example, the first tubular vessel
100 may be a vascular graft or other bypass vessel and the second
tubular vessel 120 may be an artery such as a coronary artery. The
coupler includes a tubular conduit 2905 having a proximal end 2910
and a distal end 2915, and one or more pairs of flexible members
2920 extending radially from the distal end 2915 of the tubular
conduit 2905. Each pair of flexible members 2920 includes an inner
member 2925 and an outer member 2930. The outer member has a first
end 2935, a second end 2940, and a length section 2945 extending
between the first end 2935 and the second end 2940. The inner
member 2925 is completely surrounded by the outer member 2930. The
outer member 2930 may be formed as, for example, a U-shaped member.
Similarly, the inner member 2925 also may be formed as, for
example, a U-shaped member. Of course, referring specifically to
FIGS. 145 and 146, either or both of the inner member 2925 and the
outer member 2930 may be formed to have a generally straight
configuration and, optionally, the other may have a generally
U-shape that fits around the other member. The outer member 2930
and the inner member 2925 generally extend radially from the
tubular conduit 2910 at a common length position of the tubular
conduit.
[0215] Referring again to FIG. 144 and FIG. 147, although similarly
applicable to the configurations of FIGS. 145 and 146, in use, the
distal end 2915 of the tubular conduit 2905 is inserted into the
aperture in the second vessel 120 and the inner members 2925 and
the outer members 2930 are deployed in the aperture such that the
inner members are inside of the second vessel 120 and press against
the vessel wall and the outer members are outside of the second
vessel and press against the vessel wall.
[0216] The coupler 2900 optionally may contain a slot 2950 passing
completely through the wall thickness of the tubular conduit and
passing between the proximal end 2910 and the distal end 2915. The
configuration of the slot 2950 is not limited and may be, for
example, straight and along the entire length of the tubular
conduit 2905 (FIG. 144), straight and along a portion of the length
of the tubular conduit (FIG. 148), spiral-shaped (FIG. 149), or
multiple spiral shaped slots 2950 (FIG. 150). The configuration of
the slot 2950 is selected so that the cross-sectional profile of
the tubular conduit 2905 can be reduced by, for example, being
rolled lengthwise (FIG. 151) or otherwise compressed, such as with
fingers or surgical tools, so that it can be easily inserted
through a small diameter opening. The flexible members may be
extended longitudinally to reduce its profile (FIG. 152). Referring
to FIG. 148, the slot also can be configured such that it passes
through less than the entire length of the tubular conduit 2905. In
this manner, a portion of the tubular conduit 2905 can be deformed
to reduce the cross-sectional profile of, for example, the distal
end 2915. Referring to FIGS. 153 and 154, in one method of
implanting the coupler 2900 in which no deployment tools are
needed, the physician inserts the distal end of the coupler
completely into the arteriotomy such that the inner and outer
members are positioned completely within the vessel 120 (FIG. 153).
The physician then gently pulls the coupler 2900 out of or away
from the vessel until the outer members spring back against the
vessel wall, trapping the vessel wall between the inner and outer
members (FIG. 154).
[0217] Although the vascular couplers described above have been
generally described as including petals or other members to assist
in the securing the coupler to a vessel arteriotomy, such petals
are not strictly necessary. For example, referring to FIG. 155, a
vascular coupler 3000 includes an overmolded stem 3005, an
overmolded ridge 3010, and an overmolded connecting member 3015.
The stem 3005 includes a strain relief 3020 that connects to an
elastic or superelastic/shape memory ring 3025 that is positioned
within the ridge 3010. The ring 3025 maintains an open lumen
through the coupler. The connecting member 3015 is inserted into
the arteriotomy and the coupler 3005 is adhered to the vessel 120
using, for example, an adhesive placed on a tissue contacting
surface 3030 of the ridge and/or the connecting member 3015. Of
course, additional or substitute securing methods can be used to
retain the coupler in the host vessel, such as sutures, clips, or
other methods known to those of skill in the art.
[0218] The primarily metallic vascular couplers described above may
be made of a superelastic or shape memory metal or plastic that can
be deformed during deployment to have its cross-sectional profile
reduced as described above. For example, the stem can be made of
nitinol. The inner and outer surfaces of the stem also or
optionally can be electropolished. The inner and outer surfaces of
the stem can be configured to have increased biocompatibility and
blood compatibility, such as by having a textured surface that
promotes endothelial cell growth and adhesion, as described in more
detail below.
[0219] Materials other than superelastic shape memory alloys may be
used as the stem, the inner clips, and/or the outer clips provided
they can be elastically deformed within the temperature, stress,
and strain parameters required to maximize the elastic restoring
force thereby enabling the device recover to a specific diameter
and/or geometry once deployed over or on top of the vessel or other
location. Such materials include other superelastic metal alloys,
spring stainless steel 17-7, other spring metal alloys such as
elgiloy.TM., inconel.TM., superelastic polymers, etc.
[0220] The vascular coupler could contain a single or multiple
superelastic/shape memory metallic alloy component such as a wire,
rod, hoop, tube, coil, sheet, strip, band, or other geometry in the
middle, outer, in between, side, horizontal and or vertical plane,
or combination on the device. The SE/SM elements could be located
in a single, or multiple plane configuration(s). The thickness
could be between 0.005'' to 0.040'' or other. The
superelastic/shape memory alloy material could be annealed in one
configuration during manufacture and processed (and packaged) in
another configuration. When the material is exposed to normal body
temperature (37.degree. C.), will expand to engage the vessel wall,
recovering to the optimum size, diameter and geometry to provide
acute hemostasis and mechanical securement. Alternatively, a
superelastic material could be used, being deformed/deflected
during deployment, and designed to recover and provide acute
hemostasis and mechanical securement to the vessel.
[0221] Alternative configurations and materials for the vascular
coupler are as follows. The vascular coupler could be partially or
completely fabricated from many different types of synthetic
biocompatible materials, including expanded polytetrafluoroethylene
(ePTFE), polyester (including PET), woven Dacron, polyurethane,
silicone, urethane, polyamide, polyimide, nylon, polyethylene,
collagen, composite, combination or other. Some polymer materials
could be irradiated in a desired geometry, for the shape to be
"set" into that position, that could be helpful to provide a
particular profile, and may also be helpful to prevent kinking or
closure of the lumen. A similar process using heat instead of
radiation could be used where the thermoplastic polymer is annealed
(and cooled) into a particular shape and geometry.
[0222] The vascular coupler could also be partially or completely
made from many different types of biodegradable/bioabsorbable
materials, including modified starches, gelatins, cellulose,
collagen, fibrin, fibrinogen, elastin or other connective proteins
or natural materials, polymers or copolymers such as polylactide
[poly-L-lactide (PLLA), poly-D-lactide (PDLA)], polyglycolide,
polydioxanone, polycaprolactone, polygluconate, polylactic acid
(PLA), polylactic acid-polyethylene oxide copolymers,
poly(hydroxybutyrate), polyanhydride, polyphosphoester, poly(amino
acids), poly(alpha-hydroxy acid) or related copolymers of these
materials as well as composites and combinations thereof and
combinations of other biodegradable/bioabsorbable materials.
[0223] Additionally, the vascular coupler could be partially or
completely fabricated from materials that swell, or expand when
they are exposed to a fluid (such as blood or other). These
materials include hydrophilic gels (hydrogels), foams, gelatins,
regenerated cellulose, polyethylene vinyl acetate (PEVA), as well
as composites and combinations thereof and combinations of other
biocompatible swellable or expandable materials.
[0224] It is important to understand basic terminology when
describing metals with elastic, superelastic, or shape memory
behavior. Elasticity is the ability of the metal, under a bending
load, for example, to deflect (strain) and not take a permanent
"set" when the load (stress) is removed. Common elastic metals can
strain to about two percent before they set. Superelastic metals
are unique in that they can withstand up to about ten percent
strain before taking a set. This is attributed to a
"stress-induced" phase change within the metal to allow it to
withstand such dramatic levels of strain. This is a desirable
feature in collapsible arterial anastomosis connection devices.
Depending on the composition of the metal, this temperature that
allows such a phase change can vary. And if the metal is "set" at
one temperature, and then the temperature is changed, the metal can
return to an "unset" shape. Then, upon returning to the previous
"set" temperature, the shape changes back. This is a "shape memory"
effect due to the change in temperature changing the phase within
the metal. This summary describes these different metal behaviors,
along with the compositions of various shape memory alloys.
[0225] When a metal is loaded (stressed) and undergoes, for
example, bending, it may deflect (strain) in a "springy" fashion
and tend to return to its original shape when the load is removed,
or it may tend to "set" and stay in a bent condition. This ability
to return to the original shape is a measure of the elasticity or
"resilience" of the metal. This ability for a metal to be resilient
is desirable for such things as springs, shock absorbing devices,
and even wire for orthodontic braces, where the ability to deflect,
but not deform (set) is important to maintain an applied force.
Thus, elasticity is a highly desirable feature for a flexible,
collapsible anastomosis device for connecting arterial grafts.
[0226] If, under a bending load, the metal takes a set, it is said
to have plastically (versus elastically) deformed. This is because
the imposed stress, produced by the bending load, has exceeded the
"yield strength" (stress) of the metal. Technically, this level of
stress that produces a set, is referred to as the "elastic limit",
but is about the same as the yield strength. If the applied load
increases past the yield strength of the metal, it will produce
more plasticity and can eventually break. The higher the yield
strength of the metal, the more elastic it is. "good" elastic
metals can accommodate up to about two percent strain prior to
taking a set. But this is not the only factor governing
"elasticity".
[0227] Another factor that determines the ability of a metal to
deflect to a given, desired amount, but not take a set, is the
"elastic modulus", or often called the modulus of elasticity. The
"modulus" of the metal is an inherent property. Steels, for
example, have a relatively high modulus (30 msi) while the more
flexible aluminum has a lower modulus of about 10 msi. The modulus
for titanium alloys is generally between 12 and 15 msi.
[0228] Resilience is the overall measure of elasticity or
"spring-back ability" of a metal. The ratio of the yield strength
divided by the modulus of the metal is the resilience. Although it
is one thing for a metal to be resilient, it must also have
sufficient strength for the intended service conditions.
[0229] As discussed above, when a metal is loaded, each increment
of load (stress) produces a given increment of deflection (strain)
within the metal. And the metal remains elastic if the applied is
below the yield stress. However, there is a unique class of metal
alloys that behave in an even more elastic manner. These are the
"superelastic" metals, where, for a given applied stress (load)
increment, the strain in the metal can reach 5 or 6 percent or more
without taking a set. In these type metals, the overall strain
required to produce a set can reach an impressively percent. This
phenomenon is related to a phase change within the metal, and which
is induced by the applied stress. This "stress-induced" phase
change can also allow the metal to be set at one temperature and
return to another shape at another temperature. This is a "shape
memory" effect which is discussed later.
[0230] The most common superelastic metal, used in many commercial
applications, is an alloy comprised of about equal parts of nickel
(Ni) and titanium (Ti), and has a trade name of "Nitinol". It is
also referred to as "NiTi". By slightly varying the ratios of the
nickel and titanium in nitinol, the stability of the internal
phases in the metal can be changed. Basically, there are two
phases. An "austenite" phase and a lower-temperature, "martensite"
phase. When the metal is in an austenitic phase condition and is
stressed, then a stress-induced martensite forms, resulting in the
superelasticity. This is reversible, and the original shape returns
upon release of the applied stress.
[0231] It is preferred that the Ni-to-Ti ratio in the nitinol be
selected so that the stress-induced martensite forms at ambient
temperatures for the case of superelastic brace and support
devices, which are used in ambient conditions. The specific
composition can be selected to result in the desired temperature
for the formation of the martensite phase (Ms) and the lower
temperature (Mf) at which this transformation finishes. Both the Ms
and Mf temperatures are below the temperature at which the
austenite phase is stable (As and Af). The performance of an
anastomosis connecting device can be further enhanced with the use
of superelastic materials such as nitinol. The superelasticity
allows for greatly improved collapsibility, during deployment, such
as by finger manipulation, with a surgical tool, or utilizing a
delivery device or catheter, and which will return to its intended
original shape when released within the vessel. The high degree of
flexibility is also more compatible with the stiffness of the
engaged vessel.
[0232] By manipulating the composition of nitinol, a variety of
stress-induced superelastic properties can result, and over a
desired, predetermined service temperature range. This allows the
metal to behave in a "shape memory" or "shape recovery" fashion. In
this regard, the metal is "set" to a predetermined, desired shape
at one temperature when in a martensitic condition, and which
returns to the original shape when the temperature is returned to
the austenitic temperature.
[0233] The shape memory phenomena occurs from a reversible
crystalline phase change between austenite and the
lower-temperature martensite. In addition to this transformation
occurring from an induced stress as described previously, it can,
of course, also change with temperature variations. This
transformation is reversible, but the temperatures at which these
phase changes start and finish differ depending on whether it is
heated or cooled. This difference is referred to as a hysteresis
cycle. This cycle is characterized by the four temperatures
mentioned previously, As, Af, Ms, and Mf. Upon heating from a
lower-temperature martensite, the transformation to austenite
begins at the As, and will be fully austenite at Af. And upon
cooling, austenite will begin to transform back to martensite at
the Ms temperature, and become fully martensitic at the Mf. Again,
the specific composition of the alloy can result in a desired
combination of these four transformation temperatures.
[0234] In the malleable martensitic state, the alloy can be easily
deformed (set). Then upon heating back to the austenitic
temperature, the alloy will freely recover back to it's original
shape. Then if cooled back to the martensitic state, the deformed
shape re reform. The typical sequence of utilizing this shape
memory property is to set the shape of, for example, a stent or
anastomosis coupler, while in the higher-temperature austenitic
state. Then, when cooled, deform the martensite material, and then
heat to recover the original shape.
[0235] With the background given above, it can be seen that, if the
Nitinol material requires and exceptionally tight bend, and one
that would normally exceed the elastic limit of the material, and
thus permanently deform it, a bend can be placed in the device and
the device annealed to relieve the bending stresses within the
device. Following this first bend, the device can be bent further
to produce an even sharper bend, and then re-annealed to alleviate
the stress from this additional bending. This process can be
repeated to attain the desired, sharp bend or radii that would
otherwise permanently deform the device if the bend were attempted
in a single bending event. The process for recovery from the
position of the most recent bend is then performed as described
above.
[0236] This shape memory ability is very useful for the delivery
and release of self-expanding coronary stent devices. These devices
are deformed and maintained in their martensitic state (can require
a cooling agent if Mf is below room temperature) until they are
introduced and released in the body. A warm, sterile solution,
short electrical activation, or other suitable means (free recovery
if Af is less than 37 C) and trigger the recovery to the
predetermined shape. Ideally, the material remains austenitic after
cooling to body temperature. This is achieved by choosing an alloy
composition with a hysteresis such that Ms is never reached upon
cooling to normal operating conditions (Ms below body temperature).
High-temperature martensite shape memory alloys are also an
alternative solution.
[0237] Although the example of Nitinol, discussed above, is, by
far, the most popular of the superelastic metals, there are other
alloys that can also exhibit superelastic or shape memory behavior.
These include Copper-40 at % Zinc; Copper-14 wt % Aluminum-4 wt %
Nickel; Iron-32 wt % Manganese-6 wt % Silicone; Gold-5 to 50 at %
Cadmium; Nickel-36 to 38 at % Aluminum; Iron-25 at % Platinum;
Titanium-40 at % Nickel-10 at % Copper; Manganese-5 to 35 at %
Copper; and Titanium-49 to 51 at % Nickel (Nitinol).
[0238] The unique ability of Nitinol to serve in a superelastic or
shape memory capacity, along with the excellent corrosion
resistance and biocompatibility afforded this material by the large
amount of titanium in the composition, render this alloy ideal for
anastomosis connecting devices. Such devices are designed to
connect blood vessel segments, including vascular grafts to
arteries. This alloy can be expected to allow for improved
collapsibility while being deployed, such as by finger manipulation
or by delivery within a delivery device catheter, and memory
required for the device to return to its intended service shape
when released within the blood vessel. Further, this highly elastic
alloy can allow for an inherently lower-stiffness design, and thus
less mismatch with the elasticity of the engaged blood vessel.
[0239] In summary, there are various ways of describing elasticity,
but the main criteria is the ability of the metal to return to its
initial, pre-loaded shape. Some metals can only deflect a couple
percent and remain elastic while others, such as superelastic
Nitinol, can deflect up to about ten percent. Nitinol is also
biocompatible and corrosion resistant. This unique combination of
properties allows a device made of Nitinol, such as an anastomosis
connecting device, to be fully collapsed within a delivery catheter
and be subsequently released, at a particular site within the
vessel, to form its intended service shape.
[0240] The vascular couplers formed from a sheet of Nitinol (i.e.,
without an overmold) described herein can be formed to have single
or multiple layers. To form the vascular coupler, the tube is first
processed into the desired shape. The device and/or elements (i.e.,
clips) could then the positioned over a forming fixture. The
forming fixture would have one or more surfaces where the device
and/or elements would be constrained into the final, as in vivo
deployed configuration. The annealing fixture is then partially, or
completely subjected to temperatures sufficient to cause the
desired effect. The heat source can be an oven, or salt pot. To
anneal superelastic/shape memory alloys, the temperature is
approximately 300 to 600.degree. C. After a predetermined time, the
fixture containing the SE/SM alloy elements is then removed from
the heat source (such as a salt pot) and quickly quenched in cold
water. This process may be repeated as many times as needed to make
small incremental changes in the radius, angle or other, during
each annealing cycle, to prevent over stressing the material when
securing to the fixture. Once the desired final shape has been
achieved, and the fixture is cool to the touch, the device and/or
elements are removed from the fixture for further processing.
[0241] To anneal a thermoplastic polymer, the heat must be above
the glass transition (Tg) temperature of the particular polymer.
After a predetermined time, the fixture is then removed from the
heat source (for this application, an oven) the fixture is removed
and allowed to cool gradually. Once the fixture is cool to the
touch, the device and/or elements are removed from the fixture for
further processing.
[0242] The annealing fixture may be made from a metallic material
able to withstand the annealing temperatures, and may have single
or multiple components or sections. In the case of multiple
components or sections, the various components or sections could be
held together with clamps, screws, rods combination or other, and
may have the ability to anneal devices and/or elements for a
single, or multiple devices at one time.
[0243] When thermally forming superelastic component layer, the
superelastic material(s), previously cut into the desired pattern
and/or length, are stressed and constrained into the desired
resting configuration over a mandrel, or other forming fixture
having the desired resting shape of the device depending on the
vessel size or other location where the device is intended to be
used, and secured. The material is heated to between 300 and 600
degrees (or other) Celsius for a period of time, typically between
30 seconds and 30 minutes, or other. Once the volume of
superelastic material reaches the desired temperature, the
superelastic material is quenched by inserting into chilled water
or other fluid, or otherwise allowed to return to ambient
temperature. As such the superelastic component layer(s) are
fabricated into their resting configuration. This process may be
repeated with the material being annealed in smaller increments of
bending or shaping, so as to not stress the material past its
elastic limit (approximately 8 to 10%). The superelastic/shape
memory layer(s) may be located full or partial length or width of
the device.
[0244] Any metal or metal alloy that comes in contact with blood
and/or tissue can be electropolished. Electropolishing may reduce
platelet adhesion causing thrombosis, and encourage endothelization
of the exposed metallic areas. Electropolishing also beneficially
removes or reduces flash and other artifacts from the fabrication
of the device.
[0245] The superelastic/shape memory elements could be processed
into the desired shape and configuration using several methods,
such as electron discharge machining (EDM), laser, chemical
etching, grinding, cutting, combination or other, prior to or after
the annealing process.
[0246] Superelastic/shape memory materials are available in many
configurations, from several suppliers, including, NDC (Fremont,
Calif.), Memry Corporation (Bethel, Conn.) and Shape Memory
Applications, Inc. (San Jose, Calif.).
[0247] The vascular coupler also can be partially or completely
coated with a polymer coating or covering with a polymer covering,
such as, for example, polytetrafluoroethylene, polyurethane,
polyethylene terephathalate, or other coating material, as
described herein. In general, the coating or covering provides a
blood and body compatible surface and also can be used to attach a
graft or vessel to the coupler. The covering or coating also
provides a surface through which fluid, such as blood, cannot pass,
but yet permits the coupler to have its cross-sectional profile
reduced. A coating or covering also can be used to reinforce the
anasomotic site, and not necessarily extend the entire length of
the bypass vessel.
[0248] The stem, and or other areas of the device, may be annealed
in a larger configuration than the vessel (either bypass or host)
it will be inserted into, so that once deployed, the larger
annealed size could have a greater potential contact force against
the host or bypass vessel, than if the device was sized exactly to
the vessel.
[0249] The stem region may have one or more "hinge" regions that
are designed to flex when compressed. The hinge can be an area
where the wall is reduced in thickness and or width. The hinged
regions may be located so as to assist/enable reduced cross section
deployment and or securing the device to either the bypass graft,
host vessel, or other. The stem area may be compressed and inserted
into the ID of the bypass vessel. When the stem is no longer
compressed, it will expand and engage the inside of the bypass
vessel. The outside of the stem may have an adhesive, and or a
suture tied around the outside of the bypass vessel. A simple
loading tool may be used to compress the stem of the device, or
alternatively, hemostats or other common surgical instrument may be
used. Alternatively, or in addition, the stem may have a slit or
slot to enable reducing the cross section for insertion into the ID
of the bypass vessel or other purpose.
[0250] If a substantially tubular structure (tube) is used for the
device, it may be initially round (concentric), and then processed
such that the end shape is an oval, or has two flat sides
(flattened), with the top and bottom being substantially round,
combination or other.
[0251] The host vessel tissue contacting elements that are designed
to remain on the outside of the vessel, may be annealed in a
different plane than the elements that will be on the inside, to
take into account the thickness of the vessel wall.
[0252] In loading the vascular coupler into a bypass vessel, the
bottom of the coupler may be compressed using a hemostat or other
device, to compress the stem region to enable insertion into the
end of the bypass vessel. Once inserted into the vessel, the distal
ends of the hemostat can be opened, removing the compressive force,
allowing the stem to expand radially, making contact with the
inside of the vessel. The contact/bond between the device and the
bypass vessel may be aided using a biologically acceptable adhesive
(contact or other), and or tissue engaging tabs or other that may
be biased outward. A suture may also be positioned around the
bypass vessel, at the device stem area, providing compression
between the vessel and device. For the "paper clip" stem version of
the device, the exterior vessel host vessel tissue contacting
elements may be deflected outward (to load the vessel to the
device) manually, or by using a tool.
[0253] Referring to FIG. 156, a vascular coupler 3040 is shown that
includes a deformable strain relief 3045 in the stem 3005. However,
unlike the coupler 3000, the coupler 3040 does not include a ring
3025 in the ridge 3010. The strain relief 3045 has a
circumferential portion 3050 and longitudinal members 3055.
Referring to FIG. 157, a vascular coupler 3060 includes a
longitudinal strain relief 3065 in the stem 3005. However, unlike
the strain relief 3045, the strain relief 3065 include longitudinal
members 3067 that connect to ridge members 3070 that extend
outwardly into the ridge 3010. The ridge members 3070 add support
to the ridge. Referring to FIG. 158, a vascular coupler 3080
includes the elastic ring 3025 within the ridge 3010 but does not
include a strain relief in the stem 3005. Referring to FIG. 159, a
vascular coupler 3090 includes multiple circumferential strain
relief members 3095 that are configured to prevent collapse of the
lumen of the coupler. The coupler also includes the ring 3025
within the ridge 3010. Referring to FIG. 160, a vascular coupler
3100 includes the ring 3025 and a spiral-spring strain relief
member 3105 that extends circumferentially along the length of the
stem 3005. Referring to FIG. 161, a vascular coupler 3120 includes
the ring 3030 within the ridge 3010 and a reinforcing ring 3125 to
ensure that the distal end of the coupler remains open after
implantation. Referring to FIG. 162, a vascular coupler 3130
includes a compressible spring 3135 that can be compressed to
reduce the profile of the coupler for easing deployment and
implantation. Referring to FIGS. 163-166, a vascular coupler 3150
is shown implanted within the vessel 120. The coupler 3150 includes
any of the features described above with respect to the coupler
3000, 3040, 3060, 3080, 3090, 3100, 3120, and 3130.
[0254] Referring to FIG. 167, a vascular coupler 3170 includes
strain relief members 3180 that extend along the length of the stem
3005. The strain relief members 3180 include ridge reinforcement
members 3175 and petal members 3185. The petal members 3185 and the
ridge 3010 trap and retain the vessel 120 when the coupler 3170 is
implanted within an arteriotomy. Referring to FIG. 168, a vascular
coupler 3190 similarly includes strain relief members 3180. In
contrast to the vascular coupler 3170, the strain relief members
3180 do not include the ridge reinforcement members 3175, although
they do include the petals 3185. Referring to FIG. 169, a vascular
coupler 3200 includes the ring 3025 within the ridge 3010 and a
petal ring 3205 at the base of the connecting member 3015. The ring
3025 additionally or alternatively can be configured as a hoop or a
band. The petal ring 3205 and the ridge 3010 reinforced with the
ring 3025 trap and retain the vessel 120 when the coupler 3170 is
implanted within an arteriotomy. Referring to FIG. 170, a vascular
coupler 3210 includes the ring 3025 within the ridge 3010 and
multiple extended petals 3213 that extend from the ring 3025 and
include extensions 3215 and petals 3220. Each petal 3220 extends
from an extension 3215. The ring 3025, extensions 3215, and petals
3220 maintain the patency of the coupler and retain the vessel 120
when the coupler is implanted within an arteriotomy. Referring to
FIG. 171, a vascular coupler 3230 includes a spiral strain relief
3235 that extends the length of the stem 3005, ridge 3010, and
forms petals 3236. Referring to FIG. 172, the vascular coupler 3230
can be configured with a variation of the spiral strain relief 3235
by using a criss-cross strain relief 3238 that terminates in petals
3236, the petals 3235 and strain relief 3238 providing strain
relief and preventing collapse of the stem 3005 but providing only
strain relief in the connecting section 3015. Referring to FIG.
173, a vascular coupler 3250 includes multiple strain
relief/reinforcing members 3255. The members 3255 are generally
C-shaped and include a ridge reinforcement segment 3256 and a petal
segment 3257. The combination of the ridge reinforcement segment
3256 and the petal segment 3257 retain the coupler 3250 to the
vessel 120. Referring to FIG. 174, a vascular coupler 3260 includes
a V-shaped compressible spring 3265. The spring 3265 terminates in
ridge reinforcement members 3266 that reinforce the ridge 3010. The
connecting member includes integral petals 3267 that extend
outwardly from the coupler to retain the coupler to the vessel by
pinching the vessel wall between the petals 3267 and the reinforced
ridge 3010. Referring to FIG. 175, a vascular coupler 3270 includes
the compressible spring 3265. However, in contrast to the vascular
coupler 3260, the spring 3265 terminates in the integral petals
3267 with the ridge reinforcement members 3266 positioned within
the petals 3267. The couplers 3260 and 3270 can be manually
deployed by compressing the spring inwardly, inserting the petals
into the arteriotomy, and releasing the spring to retain the
coupler within the vessel 120. Referring to FIGS. 176-178, a
vascular coupler 3300 is shown implanted within the vessel 120. The
coupler includes the stem 3005, the ridge 3010, and generic petals
3305 The coupler 3300 includes any of the features described above
with respect to the couplers 3170, 3190, 3200, 3210, 3230, 3250,
3260, and 3270. For example, the petals 3305 can be configured as
any of the petals of these couplers.
[0255] Referring to FIGS. 179-182, the vessel 100 that connects a
pair of generic couplers 123 (e.g., any coupler described herein)
can be reinforced. FIG. 179 illustrates a spiral-shaped reinforcing
member 3320 positioned around the outside of the vessel 100. FIG.
180 illustrates a ribbed reinforcing member 3330 positioned around
the outside of the vessel 100. As illustrated in FIGS. 181 and 182,
the ribbed reinforcing member 3330 includes a backbone 3335 and
alternating ribs 3340 extending from the backbone member. The ribs
can be alternating or extending from the rib at the same point
along the length of the backbone member.
[0256] Referring to FIG. 183-185, an aid or accessory that can be
used with the vascular couplers described herein is an RF aortic
punch 3400 to use as an RF cutter. The RF aortic punch 3400
includes an electrode tip 3405, a handle 3410, and a cable
connector 3415 to provide power to the electrode tip 3405. One
example of a suitable RF punch is disclosed in U.S. Patent
60/381,784, titled RF Tissue Punch, Coring Tool, and Arteriotomy
Device and Method to Houser et al, the contents of which are
incorporated herein by reference. The RF aortic punch has a similar
design as a standard aortic punch except that one or both of the
cutting edges is an electrode. The electrode is used for unipolar
or bipolar tissue cutting. The cutting is accomplished using ohmic
tissue heating, or direct resistive electrode heating. Referring to
FIG. 184, for direct resistive element heating, both conductors
3440 from the power source 3425 are connected to the punch
electrode 3405 directly heating the electrode, which has the
ability to sever the tissue. Although the electrode is described as
a singular electrode, more than one electrode can be used. The
direct resistive element heating system includes the power source
3425, the controller 3430, and the display 3435. The use of heat to
cut and capture the aortic wall tissue may have surprising and
significant clinical benefits by making a more complete
circumferential cut through the vessel wall, thereby preventing
potential leaking or oozing that can occur with most punches, once
the anastomosis has been made. Another advantage is that of the
body's natural response to the heat from the RF cutting method.
[0257] Referring to FIG. 185, for ohmic tissue heating, one
conductor may be connected to an RF power source 3455, through a
cable and coupler on the proximal end of the punch, and to the
punch electrode 3470. The other conductor is connected to a ground
pad 3465 placed on the patient's body, and also connected to the
power source 3355 by means of a cable. When the RF power is turned
on, and the electrode comes in contact with the vessel wall, the
tissue contacting the electrode is heated sufficiently to sever the
tissue. The ohmic tissue heating system further includes a
controller 3460.
[0258] Referring to FIG. 186, another aid or accessory device to
use in deploying the vascular couplers described herein is a fixed
length arteriotomy device 3480. In general, it is important to
match the length of the arteriotomy to the vascular coupler that is
to be implanted at the distal coronary anastomosis site. Making the
arteriotomy too small will make the insertion of the vascular
coupler too difficult. Similarly, making the arteriotomy too long
will make acute hemostasis very difficult. As such, advantages
arise from providing an automatic arteriotomy device because the
surgeon can safely, quickly, and predictably make a specific length
cut on a beating heart. The arteriotomy device 3480 includes a
cutting element 3485, a handle 3490, and a plunger 3495. Pressing
down on the plunger presses and cuts tissue against the cutting
element.
[0259] Several designs of automatic arteriotomy devices can be
used. The designs include: (1) a modified version of the aortic
punch that cuts only the vessel wall and does not remove tissue;
(2) a specific/specified length Potts type scissors that, for
example, has reference length markings on the blade; (3) other
scissors or cutting devices having reference length markings; or
(4) a scalpel edged device that is advanced through the vessel wall
and has a stop to prevent the scalpel blade from advancing too far.
These or other devices are used to make a specific length cut
through the vessel wall while at the same time preventing posterior
vessel perforation. In addition, the automatic arteriotomy device
may have one or more electrodes on the cutting surface and uses RF
energy to make the cut in a similar manner as the aortic punch
described above. Referring to FIGS. 187-192, a side-to-side
vascular coupler is fabricated from a tube 3500. The tube 3500 is
machined to form a central ridge or backbone 3510 and lateral ribs
3505 that define a central lumen 3515 (FIGS. 188 and 189). The ribs
3505 then are bent to form a vascular coupler 3520 that includes
petals 3525 that extend from a lumen 3530. The coupler includes a
first end 3535 and a second end 3540. The side-to-side coupler can
have petals that are apposed (FIG. 191) or alternating (FIG.
192).
[0260] In one general aspect, the side-to-side vascular coupler is
configured as a tubular structure with predominately linear slots
(through the wall) on both ends of the tube. The slots do not
continue along the full length of the tube, leaving a section
(e.g., in the middle) of the tube intact. After further processing,
the device has the ability to be constrained into a smaller cross
sectional profile during insertion and positioning using a
deployment device. Once the deployment device is at the desired
location, the constraining force is removed and the side-to-side
device reverts to its annealed geometry and profile, engaging and
compressing the tissue together, between the end elements. The
tissue contacting/engaging elements on one or both ends of the
tubular device may be formed to be aligned with each other, or
offset, depending on the application.
[0261] The vascular coupler may be made of a superelastic/shape
memory alloys such as Nitinol, as well as the other materials
described herein. The side-to-side vascular coupler may be
completely or partially coated with ePTFE or suitable other
material. The vascular coupler may be coated with other materials
to assist with the bonding of the tissue contacting regions, and
may include therapeutic materials for acute or chronic elution
treatment, as described herein.
[0262] In fabricating the vascular coupler, a Nitinol tube is cut
to length, linear slots are made through the wall of the tube in
the desired geometry using laser machining, wire EDM, etching,
photo-etching, a combination of these methods, or other suitable
method. The tube is then placed into or on the annealing fixture
and annealed into the final, post deployed configuration. Once the
heat cycle has been completed, the tube is then quenched in cold
water and removed from the fixture. The tube/side-to-side vascular
coupler can be further processed if desired. Further processing can
include, but is not limited to, electropolishing (i.e., especially
desirable if the device will be in contact with blood) and coating
(therapeutic or other) or over molding.
[0263] The side-to-side vascular coupler can be deployed with a
deployment device such that the vascular coupler is advanced into
position and deployed using a catheter or hand held device,
specifically designed for the side-to-side device. Modifications of
the catheter and hand held deployment devices may be used for
endoscopic and laparoscopic procedures. The tip of the deployment
device may have a "Screw, or corkscrew" type configuration, so that
advancement through tissue can occur without significant forward
pressure or force being applied--instead, the device can be
advanced by rotation of the deployment device.
[0264] Referring to FIGS. 193-197, a deployment method for
deploying the side-to-side vascular coupler involves a catheter or
surgical instrument that has the ability to puncture one or more
layers of tissue with the distal tip or through a lumen containing
a needle or other sharp pointed device, hold the posterior section
of the second layer of tissue against the first tissue layer by the
use of one or more guide wire(s) with an acute bend angle (such as
90.degree.), or steering capabilities, or other, while the distal
section of the catheter or surgical instrument is advanced to a
predetermined location (location determination may be assisted with
geometric "bumps", or other on the outside of the catheter or
instrument, to allow tactile feedback to confirm that the catheter
or instrument is in the correct location for deployment), while the
connecting device is allowed to expand and be deployed at the
desired location, through the puncture, positioning and compressing
the two layers of tissue together, by either the removal of a
constraining force (such as a moveable sheath), or the advancement
of a plunger stylet, to engage and deploy the connecting device
from in between the outside of an inner tube and inside an outer
tube catheter or instrument. The catheter or instrument could have
multiple full-length lumens that could be used for a variety of
purposes, such as sensors (e.g., pressure, tissue contact,
electrical, other), or other to assist with the catheter or
instrument location, tissue puncturing, visualization,
monitor/confirm connecting device deployment, therapeutic fluid or
material delivery, or any diagnostic or therapeutic purpose. The
catheter or instrument may have steering capabilities, or the use
of a steerable guide wire may be used. The steering controls,
sensors or other could be operated from the side or proximal end of
the catheter or instrument.
[0265] In particular. the side-to-side coupler 3520 can be used to
provide a connection between adjacent vessel walls 3550 and 3555
(FIG. 193). Referring to FIG. 194, a sheathed deployment tool 3560
includes a needle 3565. The needle 3565 is advanced through the
vessel walls 3550 and 3555 to form openings in the vessel walls.
The deployment too 3560 then is advanced through the opening until
the coupler 3520 spans the vessel walls 3550 and 3555 (FIG. 195). A
distal portion 3570 of the deployment tool 3560 then is extended
from the tool (FIG. 196), thereby allowing the coupler 3520 to
expand and connect the two vessel walls 3550 and 3555 (FIG.
197).
[0266] Referring to FIGS. 198-203, a configuration is presented for
a low profile coupler 3600. The coupler 3600 includes a stem 3610
having a slot 3605 around which a tube 3615 (e.g., textile
material, overmold, etc.) is adhered. However, the entirety of the
tube 3615 is not adhered to the stem 3610. As such, a portion of
the stem 3610 can be coiled (FIG. 199) or folded (FIG. 200) with a
portion of the circumference of the tube unattached and extending
away from the stem. The slot 3605 forms slot edges 3625 that are
separated away from each other when the coupler is coiled or
folded. As illustrated in FIGS. 201 and 202, the stem 3610 can be
folded in an S-shape 3640 with the tube 3615 folded into a reduced
diameter section 3650. Referring to FIG. 203, a related coupler
3660 can include a stem 3665 that includes preinstalled sutures
3675 passing through the stem and used to attach the coupler 3660
to the vessel. The coupler 3660 can be covered with the tube 3615
or any other overmold or coating described herein.
[0267] Referring to FIGS. 204-208, an aid or accessory that can be
used in implanting the vascular couplers described herein is an
aortic punch 3700 that is used to cut and capture a portion of
aorta wall at the desired site of the proximal anastomosis. A
commonly used aortic punch is available from Scanlan International
(St. Paul, Minn.) as well as from other companies. The tip of the
punch is blunt to prevent perforation of the posterior vessel wall.
A reduced diameter section of the punch is located just proximal of
the distal tip. The punch has an outer tubular shaft that when the
punch is actuated, advances over the inner shaft, past the distal
tip, cutting and capturing the tissue on the outside of the inner
shaft, and inside the outer tubular shaft.
[0268] An initial incision using a scalpel blade is made through
the aorta, at the site of the proximal anastomosis. The tip of the
aortic punch then is inserted into the incision, and the punch is
actuated, cutting and capturing a round disc of the wall of the
aorta. The vascular coupler then is inserted, and deployed into and
through the opening created in the aorta.
[0269] To place the vascular couplers described herein, an
arteriotomy typically is formed. To prevent excessive blood loss
through the arteriotomy, an occluding device can be used. For
example, referring to FIGS. 204 and 205, a tissue punch 3700
includes a handle 3705, a slidable tube 3710, a cutting element
3715, and a cutting disc 3720. The handle 3705 is generally tubular
and includes a pair of handles or eyelets 3730 that are integrally
mounted to a tube 3735. The tube 3735 has an inner channel 3740
that passes between an open distal end 3745 and an open proximal
end 3750. The slidable tube 3710 fits within the channel 3740,
includes a proximal end 3755, a distal end 3760, and a tubular
segment 3765 passing between the proximal end and the distal end.
The cutting element 3715 has a sharp edge 3785 that cuts tissue.
Referring also to FIGS. 206 and 207, the punch 3700 also includes
an occluder 3787 that includes occluding ball 3790 and an occluding
stop 3791. The occluder 3787 is a separate piece that slides onto
the distal end of the punch. The occluder 3787 includes a
through-channel 3793 that passes between a proximal end 3794 and a
distal end 3795. The proximal end 3794 and the distal end 3795 of
the channel are configured to reduce fluid flow through the channel
when the occluder is inserted into a vessel. For example, the ends
can be formed as slits that will fit and slide over the punch 3700
but nonetheless reduce fluid flow through the channel 3793.
[0270] In use, occluder 3787 is slidably installed over the distal
end of the punch 3700 and the cutting disc 3720 is positioned
within a vessel through a small opening in the vessel. Then, the
slidable tube 3710 is advanced to advance the cutting element 3715
towards the cutting disc 3720, which cuts tissue positioned between
the cutting element and the cutting disc. After the cut is made,
the punch is advanced to position the occluding ball 3790 against
the opening to prevent excessive bleeding.
[0271] The size of the occluding ball 3790 can be of a similar size
as the cutting disc to fit against the vessel. The occluding ball
3790 can be fully inserted into the vessel such that the
interaction of the occluding stop 3791 rests against the vessel to
reduce blood loss. If the ball is positioned within the vessel and
the stop is positioned against the vessel wall, the punch can be
slidably withdrawn from the occluder and minimal blood leakage
results.
[0272] The punch 3700 also can be configured to have a power source
that heats the cutting element such that the tubular vessel tissue
is mechanically cut and thermally cut. The shaft or handle of the
punch/coring/arteriotomy device may act as a guide for a localized
tissue stabilizer, introducer (splitable or tearable, or with
another removable means), occluder, combination of these, or any
other device for any desired purpose, before, during, and/or after
the cutting process.
[0273] Referring to FIG. 208, a hand-held occluder 3800 can be used
to occlude an opening in a vessel. The occluder 3800 includes a
handle 3805, an occluder ball 3810, and an occluder surface 3815.
In use, the punch 3700, or similar device, is used to form an
opening in the vessel. To reduce blood loss, the physician quickly
inserts the occluder ball 3810 into the opening and rests the
occluder surface 3815 against the vessel wall. The physician then
removes the occluder 3800 when, for example, a vascular coupler is
to be inserted.
[0274] The vascular couplers described herein typically are or can
be part of a system with various accessories. For example, a
vascular coupler can be used with a graft, adhesive materials,
therapeutic agents, and radiopaque materials.
[0275] The vascular couplers could be used with harvested
biological grafts such as the internal mammary artery (IMA), radial
artery, saphenous vein, or other. Additionally, grafts made from
various other biological materials, or combination of biological
and synthetic materials, may also be used. Synthetic vessels
include Cardiopass.TM. from Cardiotech (Woburn, Mass.) and Aria.TM.
from Thoratec (Pleasanton, Calif.), as well as others.
[0276] The device could have a biocompatible contact adhesive or
other material to bond or secure the device to the vessel, sealing
the anastomosis site. In addition, adhesives may be used to secure,
or assist in securing the bypass graft to the coupler. The
adhesive/bonding compounds/solutions could be added during the
manufacturing process, just prior to deployment, or after the
device has been deployed. The bonding materials could be in the
form of a liquid, semi solid, or solid. Suitable bonding materials
include gels, foams and microporous mesh. Suitable adhesives
include acrylates, cyanoacrylates, epoxies, fibrin-based adhesives,
other biological based adhesives, UV light and/or heat activated or
other specialized adhesives. The adhesive could bond on initial
contact, or longer, to allow repositioning if desired. The
preferred adhesive may be a crystalline polymer that changes from a
non-tacky crystalline state to an adhesive gel state when the
temperature is raised from room temperature to body temperature.
Such material is available under the trade name Intillemer.TM.
adhesive, available from Landec Corp. as well as composites and
combinations thereof and combinations of other materials. Suppliers
of surgical adhesives include, but aren't limited to, Plasto
(Dijon, France), Haemacure (Montreal, Canada), Cohesion (Palo Alto,
Calif.), Cryolife (Kennesaw, Ga.), TissueLink (Dover, N.H.), and
others. To increase the work time of the adhesive or allow
repositioning of the vascular coupler after it has been deployed,
the adhesive can be blended with a material, such as a starch or
other material, that dissolves and retards or delays bonding to
allow repositioning of the coupler after it has been deployed. A
degradable coating can be placed over the adhesive coating so that
it degrades and exposes the adhesive.
[0277] The vascular couplers described herein may be coated with
materials such as Parylene or other hydrophilic materials that are
biologically inert and reduce surface friction. Another method to
reduce surface tension for metallic or metallic alloy couplers or
overmolded couplers with metallic or metallic alloy elements or
components is to chemically polish or electropolish those surfaces
that will come in contact with blood or tissue. Sandblasting,
beadblasting or other may be performed prior to polishing. It is
believed that chemical polishing or electropolishing reduces
platelet adhesion because of the smooth surface that results.
Chemical polishing and or electropolishing process can also be used
as an effective way to reduce the thickness of metal or metal alloy
coupler components.
[0278] The coupler device may incorporate one or more coatings,
materials, compounds, substances, drugs, therapeutic agents, etc.
that positively affect healing at the site, at and or near where
the device is00 deployed, either incorporated into the structure
forming the device, incorporated into a coating, or both.
Thromoboresistance materials, antiproliferative materials, or other
coatings intended to prevent thrombosis (acute and or chronic),
hyperplasia, platelet aggregation, or other negative response, at
or near the attachment of the bypass graft, as well as at or near
the implantation site of the coupler through the host vessel. The
coatings, materials, compounds, substances, drugs, therapeutic
agents, etc. may be used by themselves, and/or contained in a
carrier such as a polymeric matrix, starch, or other suitable
material or method. The coatings may be liquid, gel, film, uncured,
partially cured, cured, combination or other suitable form.
[0279] Coatings on the coupler may be used to deliver therapeutic
and pharmaceutic agents include (but are not limited to):
antiproliferative/antimitotic agents including natural products
such as vinca alkaloids (i.e. vinblastine, vincristine, and
vinorelbine), paclitaxel, epidipodophyllotoxins (i.e. etoposide,
teniposide), antibiotics (dactinomycin (actinomycin D)
daunorubicin, doxorubicin and idarubicin), anthracyclines,
mitoxantrone, bleomycins, plicamycin (mithramycin) and mitomycin,
enzymes (L-asparaginase which systemically metabolizes L-asparagine
and deprives cells which do not have the capacity to synthesize
their own asparagine); antiplatelet agents such as G(GP)
II.sub.b/III.sub.a inhibitors and vitronectin receptor antagonists;
antiproliferative/antimitotic alkylating agents such as nitrogen
mustards (mechlorethamine, cyclophosphamide and analogs, melphalan,
chlorambucil), ethylenimines and methylmelamines
(hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan,
nirtosoureas (carmustine (BCNU) and analogs, streptozocin),
trazenes-dacarbazinine (DTIC); antiproliferative/antimitotic
antimetabolites such as folic acid analogs (methotrexate),
pyrimidine analogs (fluorouracil, floxuridine, and cytarabine),
purine analogs and related inhibitors (mercaptopurine, thioguanine,
pentostatin and 2-chlorodeoxyadenosine {cladribine}); platinum
coordination complexes (cisplatin, carboplatin), procarbazine,
hydroxyurea, mitotane, aminoglutethimide; hormones (i.e. estrogen);
anticoagulants (heparin, synthetic heparin salts and other
inhibitors of thrombin); fibrinolytic agents (such as tissue
plasminogen activator, streptokinase and urokinase), aspirin,
dipyridamole, ticlopidine, clopidogrel, abciximab; antimigratory;
antisecretory (breveldin); anti-inflammatory: such as
adrenocortical steroids (cortisol, cortisone, fludrocortisone,
prednisone, prednisolone, 6.alpha.-methylprednisolone,
triamcinolone, betamethasone, and dexamethasone), non-steroidal
agents (salicylic acid derivatives i.e. aspirin; para-aminophenol
derivatives i.e. acetominophen; indole and indene acetic acids
(indomethacin, sulindac, and etodalac), heteroaryl acetic acids
(tolmetin, diclofenac, and ketorolac), arylpropionic acids
(ibuprofen and derivatives), anthranilic acids (mefenamic acid, and
meclofenamic acid), enolic acids (piroxicam, tenoxicam,
phenylbutazone, and oxyphenthatrazone), nabumetone, gold compounds
(auranofin, aurothioglucose, gold sodium thiomalate);
immunosuppressives: (cyclosporine, tacrolimus (FK-506), sirolimus
(rapamycin), azathioprine, mycophenolate mofetil); angiogenic
agents: vascular endothelial growth factor (VEGF), fibroblast
growth factor (FGF); angiotensin receptor blockers; nitric oxide
donors; anti-sense oligionucleotides and combinations thereof; cell
cycle inhibitors, mTOR inhibitors, and growth factor signal
transduction kinase inhibitors. Alternatively, a clot promoter may
be used, such as protamine sulphate or calcium hydroxide.
Endothelial cells may also be added to the coupler device.
[0280] The therapeutic compounds/solutions may be blended with the
device base materials during fabrication, applied just prior to
deployment, or after the device has been deployed.
[0281] The therapeutic materials may be located on, through,
inside, or combination of the device in holes, grooves, slots (or
other indentations) or designs. For example, the surface under the
vessel reinforcement ridge, as well as the under ridge hemostatic
gasket may have partial or complete holes, grooves, or other
indentations, filled with a therapeutic substance, in contact with
the host vessel tissue. In addition, the area of the coupler that
comes in contact with the bypass vessel may also incorporate this
feature. The petals may also have partial or complete holes, slots,
grooves, or other filled with a therapeutic substance, or simply
coated on the outside surfaces. This design allows direct contact
of the therapeutic substance, while maintaining the functional
ability of the coupler or coupler component. Combinations of
therapeutic substances or coatings may be used on the same coupler.
For example, a more viscous (gel or other) therapeutic substance
may be used to fill the partial or complete holes (or other) on the
vessel reinforcing ridge and hemostatic gasket under the ridge,
while the petals are coated with a less viscous (liquid) material.
The therapeutic substance may be the same, or a combination of more
than one type used on a single coupler. The coatings may be
designed to provide benefits acutely, and/or over a period of time.
The coatings, materials, compounds, substances, therapeutic agents,
etc. may be desired to be static, and/or eluding. The coatings,
materials, compounds, substances, therapeutic agents, etc. elutes
from the coated (or embedded) device (or component) over time and
enters the surrounding tissue. The coatings, materials, compounds,
substances, drugs, therapeutic agents, etc. preferably remain on
the coupler for at least three days, and up to approximately six
months, and more preferably between seven and thirty days.
[0282] Post device fabrication coating methods include, but are not
limited to, spin coating, RF-plasma polymerization, dipping,
spraying, brushing, submerging the devices into a beaker containing
a therapeutic solution while inside a vacuum chamber to permeate
the device material, etc.
[0283] Alternatively, or in combination with the above therapeutic
substances, a material such as platinum, gold, tantalum, tin,
tin-indium, zirconium, zirconium alloy, zirconium oxide, zirconium
nitrate, phosphatidyl-choline, pyrolytic carbon, combination or
other material, may be deposited onto the coupler surface using
electroplating, sputtering vacuum evaporation, ion assisted beam
deposition, vapor deposition, silver doping, boronation techniques,
or other coating process.
[0284] In addition to the above therapeutic methods and materials,
similar and additional methods of coating and materials are
described in detail in U.S. Patent Application No. 2002/0133183,
the contents of which are incorporated in their entirety by
reference.
[0285] Radiopaque material such as barium sulfate, bismuth
trioxide, tantalum or other can be added to the vascular couplers,
reinforcement structure (e.g. the overmold) or bonding material.
Additionally, platinum, gold, or other material may be added to the
coupler by sputter coating, ion deposition, vapor deposition,
combination, or other process.
[0286] The vascular couplers described above can be used with
various accessories, as necessary, to improve the outcome for the
patient receiving the coupler. For example, the bypass graft can be
reinforced with a vessel reinforcement device to prevent kinking,
collapsing, or other types of restrictions to blood flow. Examples
are provided in the figures. Also, the reinforcement device could
prevent bypass graft vessel over expansion once blood flow has been
reestablished. The reinforcement device can be used with any
anastomosis type, such as a coupler, staple, suture, etc.
Similarly, the vessel reinforcement device can be used with
harvested biological grafts such as the internal mammary artery
(IMA), radial artery, saphenous vein, or other. Additionally, the
vessel reinforcement device can be used with grafts made from other
biological materials, or combinations of biological and synthetic
materials.
[0287] The vessel reinforcement device may be used on the outside
or inside of the bypass graft, and may fabricated with a contact
adhesive, as described herein, and or therapeutic material, as also
described herein, on the tissue contacting surfaces. The adhesive
may be applied after the bypass graft has been secured, before or
after blood flow has been reestablished.
[0288] The vessel reinforcement device may be of a single piece
configuration, or may be fabricated from multiple pieces that
overlap. The reinforcement, or reinforcements may be as long as the
entire length of the bypass graft, or only at the two ends of the
anastomosis to function as a strain relief. The vessel
reinforcement device can be placed around the bypass graft before
the second end of the graft is secured, or after both ends of the
bypass graft has been secured if using a version of the
reinforcement device that allows side access. The vessel
reinforcement device may have a consistent diameter and geometry,
or the ends (i.e., the site of the anastomosis) may be flared to
fit over the anastomosis to thereby function as an anastomosis
reinforcement device. The vessel reinforcement device may be used
as a side access version that has the ends directly oppose each
other, although they may be offset.
[0289] The vessel reinforcement device may be partially or
completely made of metal, metal alloy (such as nitinol), polymer
(such as ePTFE), combination of these or other suitable material.
The device materials could be in the form of, for example, a wire,
hoop, oval, rod, band, ribbon, tube, sheet, combination of these or
other suitable shape. Additionally, the materials could be formed
in a wound, coiled, undulated, sinusoidal, braided, combination of
these or other suitable configuration.
[0290] The core material, which may be, for example, nitinol or
other suitable material, is annealed as described herein over a
mandrel matching the outer diameter of the bypass graft vessel. The
geometry of the mandrel may be round, oval, or of another suitable
shape, and may have a consistent size and geometry, or a larger
diameter and/or shape, at one or both ends.
[0291] The vessel reinforcement device may be partially or
completely coated or over molded using several methods and
processes including sintering, molding (such as injection molding),
casting, adhesive bonding, laminating, dip coating, spraying as
well as composites and combinations thereof and combinations of
other methods and processes.
[0292] Another accessory to the vascular coupler is a deployment
device. Examples of deployment devices have been described above.
In general, the vascular coupler is radially compressible in some
configurations and can be deployed using fingers, standard surgical
instruments (including Rongeur clamp), modified surgical instrument
or specially designed tools. Specially designed tools include
modified surgical instruments (length, contact area, compression
force, compression diameter, etc.), as well as tools/devices
specifically designed to compress the cross section of the
anastomotic device while being advancing through a hollow, tapered
tube. The anastomosis device could be advanced through the
deployment tool by an elongated stylet that attaches to the outside
of the anastomosis device, inside or outside of the deployment
tool. Advancement from outside the deployment tool, using a stylet
or plunger, could be accomplished by way of a slot through the wall
of the funnel type deployment tool.
[0293] The deployment tool may be designed to deflect some or all
of the interior tissue engagement elements (i.e., inner or outer
clips) into a position that assists deployment (i.e., forward,
backward, or other suitable position). Once deployed inside the
vessel, the device is removed from the vascular coupler.
[0294] The deployment tools and devices may have the ability for
the distal end to be steered (e.g., controllable from the proximal
end of the tool or device) while having the ability to compress the
vascular coupler during deployment, and release the coupler once it
is positioned in the desired location within the vessel. This
version of a deployment tool is particularly useful during
minimally invasive, endoscopic and robotically assisted surgery, or
other where access space within the chest cavity is limited.
Steering capability can be accomplished using one or more pull
wires attached to a ring, collar, flat leaf spring, or other member
that is designed to deflect when the pull wire is pulled.
Alternatively, the distal section of the deployment tool/device can
be formed in a curve, and a straight rod or stylet can be advanced
from the proximal end, towards the distal end, straightening the
distal end. Another option is to advance a preformed curve, or
steerable device, into a lumen of the deployment tool/device. A
clip that can be removed from the side after deployment also can be
used.
[0295] The vascular coupler is versatile and can be deployed in a
number of methods, some of which have been described above or are
described below. To access the heart, the surgeon uses a
thoracotomy, thoracostomy, or median sternotomy, or other suitable
surgical approaches. The vascular coupler and accessories described
herein can be used with cardiopulmonary support, beating heart,
open field, minimally invasive, endoscopic, laparoscopic and
robotically assisted surgery, or other cardiovascular
technique.
[0296] The bypass graft is prepared by cutting a graft to the
desired length, and the ends are cut to the desired angle (e.g., 30
degrees or other suitable angle). Further, additional cuts, such as
a longitudinal cut, may also be made to the ends of the graft to
produce the desired final geometry, or for other surgical or
therapeutic purposes. The vascular coupler is sized according to
the type, size and anastomosis location. The vascular coupler then
is loaded and secured to the bypass graft by way of securing
members, an adhesive in and/or on the tissue contacting surfaces,
and/or by using one or more sutures (e.g., tissue penetrating or
non-penetrating sutures). Alternatively, adhesive can be applied to
the vascular coupler after the coupler has been loaded and secured
to the bypass graft. The tip of a vascular dilator or other
suitable instrument may be inserted into the bypass graft lumen,
gently expanding the end diameter of the graft into contact with
the inner diameter of the vascular coupler, securing the coupler to
the bypass graft. Alternatively, the bypass graft may be positioned
and secured over the vascular coupler, and secured with adhesive
already on or in the coupler, and/or may be applied after
positioning. The adhesive used typically will be selected for its
ability to withstand submersion in papaverine or other solution
just prior to implantation.
[0297] The tissue may need to be stabilized. For example, a
localized tissue-stabilizing device may be used during the coronary
bypass procedure. One or more stabilizing devices could be
positioned on the surface of the heart, in parallel with the
coronary artery, at the site of the anastomosis. The stabilizing
devices can access the internal cavity through one or more
locations, and can be attached on the proximal end to a retractor,
or other arm, rail or other stabile platform, inside or outside of
the patient's body. The localized tissue stabilizer may be
positioned, adjusted, and locked into any direction and position.
The adjustment includes, but is not limited to, the width in
between the tissue contacting sections, and the amount of
compression and stabilization on the heart surface.
[0298] Initially, a proximal aortotomy is made in the aorta. This
generally is termed the proximal anastomosis site. The initial
puncture is typically made in the aorta using a scalpel blade,
followed by rapid insertion of an aortic punch at the site of the
incision. The punch is used to create a hole of the appropriate
size and geometry. Once the hole has been made, the punch is
removed and the proximal vascular coupler with an attached bypass
graft is compressed and inserted into the opening. The compressing
or restraining force on the vascular coupler then is removed so
that the vascular coupler is allowed to expand and engage the
horizontal and vertical planes of the anastomosis site. This
engagement creates a hemostatic seal between the wall of the aorta
and the anastomotic device.
[0299] Alternatively, an aortic punch with a forward leading edge
scalpel blade, or other sharp point can be used to form the
aortotomy. Similarly, an aortic punch that utilizes RF energy to
produce the arteriotomy can be used and may have clinical benefits
by reducing the amount of vessel injury response at the site of the
anastomosis by sealing the cut area. Other potential benefits may
result from using RF energy to form the aortotomy.
[0300] The surgeon next forms a distal anastomosis, typically in a
coronary artery. This site is generally termed the distal
anastomosis site. The arteriotomy is typically created using the
tip of a scalpel blade for the initial puncture, and then using
surgical scissors (e.g., Potts type or other suitable scissors) to
increase the longitudinal length of the incision. The scissors may
include reference measurement numbers that the surgeon can use when
creating the arteriotomy. Once the arteriotomy has been made, the
anastomosis site maybe held open with a spreader, making it easier
for the device to be inserted.
[0301] Alternatively, an automatic arteriotomy device may be used.
The device would have the ability to make a predetermined length
cut, preventing the arteriotomy from being made too long. As noted
above, if the arteriotomy is too long, it may be difficult to
achieve hemostasis after the device has been deployed.
[0302] For most coronary artery bypass grafting (CABG) procedures,
the distal (coronary) anastomosis is performed first, followed by
the proximal (aorta) connection. Once the bypass graft has been
prepped, the end of the anastomosis device (containing the end of
the graft) is compressed to produce a smaller cross section and
inserted into the coronary artery through the arteriotomy. The
device can be compressed by the surgeon using fingers, a common
surgical tool, a modified surgical tool, or special deployment
tool. The anastomosis device has geometric design features and
other that prevents positioning the device too far into the artery,
and is designed to expand and engage the artery wall (vertical, and
or horizontal engagement), once the compressive force has been
removed. Once positioned, the device can be held in place as the
adhesive, on or in the tissue contacting surfaces, cures, providing
acute hemostasis and mechanical securement to the arterial wall. A
similar process is used to make the proximal (aorta) anastomosis.
Acute hemostasis can also be realized by mechanical expansion, and
or geometric interference fit alone.
[0303] Additional securement/reinforcement can be used (if
desired). For example, a biocompatible adhesive can be applied
around the site of the anastomosis, a suture (such as a purse
string or other type of configuration) can be applied, combination
of these or other suitable methods.
[0304] External strain relief can be positioned around the bypass
graft before, during or after the CABG procedure has been
completed. Adhesive could be used to bond the securement
device/strain relief to the bypass vessel.
[0305] There are additional techniques that are typically
considered when deploying the vascular coupler. These techniques
are the push in/pull out technique and the deflection
technique.
[0306] The push in/pull out technique has been briefly described
above, but is presented here in greater detail. When inserting
vascular coupler into the hole or slot of the vessel, the hinged
elements will tend to deflect backwards until the device is inside
the target site. The vascular coupler can then be gently pulled
back to "seat," or position in the final location between the
tissue (vessel) wall. The longer hinged elements, petals, or clips
(i.e., inner members having, for example a U-shape or paper clip
configuration) prevent the device from coming out of the target
area when pulling back. Then, when further gently retracting the
vascular coupler away from the vessel, the shorter, outer elements
(i.e., paper clip-shaped element, U-shaped element) will be
released to spring back against the outer wall of the vessel as
soon as it is out of the vessel and the larger, inner members will
be released outwardly to compress the vessel between them upon
release. If a ridge configuration is used instead of the hinged
outer elements, the hinged inner elements will compress the vessel
wall between the ridge and the inner elements.
[0307] The deflection method requires the use of a disposable,
single use only, circular clip or partial ring ("C" geometry, or
other), designed to deflect a portion, or the complete hinged
element, forward, backward, or combination during insertion. The
width of the deployment clip is shorter than the length of the
hinged elements, and is removed, preferably from the side, once the
distal ends of the hinged elements are inside the target area
(i.e., vessel). This deployment tool is described in greater detail
above.
[0308] The distance between the overmolded ridge/tissue
contacting/reinforcing ridge, and the top of the petals is
anticipated to be available in different distances, to produce
different compressive forces--depending on the vessel thickness,
the shorter the distance between the ridge and petals, the higher
the compression between the outside and inside of the vessel. This
distance may also be adjustable just prior to implantation.
Availability to optimally compress several different vessel
thicknesses, custom and or adjustable vessel compression feature.
Tissue compression modified by different ridge to petal
distances.
[0309] The securing members and petals can be individual elements,
or connected, partially or completely continuous. The securing
members and petals may be made from the same or different materials
(for example, the petals can be made from nitinol, and the securing
members can be made from stainless steel).
[0310] There are additional utilities and uses for the vascular
coupler. For example, there can be a sutured anastomosis site
reinforcement. In this configuration, a version of the vascular
coupler (and or strain relief) with or without side access slit or
other, to be placed (from the side or over the top) and secured to
site after the bypass graft to host vessel anastomosis has been
sutured, to prevent kinking, bypass graft closure, vessel
"ballooning," due to a compliance mismatch, etc. Another use is to
create an anastomosis through a graft that has been deployed in the
abdominal aorta, reattaching vessels that would have otherwise been
occluded by the graft. The opposite end could be attached using an
end-to-end anastomosis device.
[0311] The vascular coupler can be used as an arterial to venous
shunt for hemodialysis, AV fistula, and pulmonary uses. The
vascular coupler and techniques can be used for cardiovascular,
gastrointestinal, neurological, reproductive, lymphatic,
respiratory or other applications where partial or complete,
temporary or permanent closure, compression, sealing or
reinforcement is desired. Additionally, any lumen, duct, organ,
hollow body organs or cavity, or other structures or tissues, where
partial or complete, temporary or permanent sealing, crimping,
compression, plugging, reinforcement or other purpose is desired.
The coupler, with or without modifications, may be used as a stent
in an ostium anywhere in the body, but especially in the aortic
ostium. The expanding members could act as a stop, so as not to
insert the stent too far into the coronary artery. The coupler can
be deployed either percutaneously (with a catheter), or during a
surgical procedure with a hand held tool, or by hand.
[0312] Alternatively, the device could be used as a conduit,
conduit support and or reinforcement by itself, or used with a
synthetic and or autogenous/autologous conduit or lumen. For
conduit or conduit reinforcement applications, the material and
design used would be sufficiently flexible, but resistant to
kinking and or compressive closure. The device may be used
completely or partially, outside, inside, in between, or
combination with any lumen, vessel, duct, organ, hollow body
organs, cavity, and or other structures or tissues within the
body.
[0313] The coupler may be closed off if the bypass graft becomes
occluded, or for any other reason, by the use of a cap, clamp,
adhesive, combination or other method. A new bypass graft may be
attached to the original coupler, or attached to a new coupler and
inserted inside or near the original coupler. If the new coupler is
intended to be inserted into the original coupler, the new coupler
may be adapted to be secured inside by a gasket type material
around the outside (to produce a mechanical and fluid tight seal),
engaging elements, interlocking elements, adhesive, combination or
other suitable design and method. The coupler also can be used as a
temporary holding device for indwelling catheters, cannula,
introducers or other devices. The coupler may be used to hold a
catheter or other, at a fixed or movable length from the outside of
a patient. The catheter or other may be inserted through the center
of the coupler, with the tissue contacting ridge attached to the
skin using an adhesive, suture(s), combination or other. The inside
of the coupler may have a valve, ring, gasket or other, that
provides fluid sealing as well as mechanical interference fit
between the inside of the coupler and the outside of the catheter
or other device.
[0314] Alternatively, the coupler may be configured to compress
onto itself, providing closure, compression, sealing or
reinforcement for any lumen, duct, organ, hollow body organs or
cavity, or other structures or tissues, where partial or complete,
temporary or permanent sealing, crimping, compression, plugging,
reinforcement or other purpose is desired.
[0315] The vascular coupler also can have the following features,
concepts, and configurations, as necessary and desirable. For
example, the vascular coupler can be partially or completely made
using several methods and processes including extrusion, sintering,
molding (injection and other), casting, adhesive bonding,
laminating, dip coating, spraying as well as composites and
combinations thereof and combinations of other methods and
processes.
[0316] The vascular coupler can be fabricated using
injection-molding or overmolding techniques. The molds would be
designed to mold the device material, inside, outside, in-between,
around, etc. the superelastic/shape memory (or other material)
elements, making the elements an integral part of the device. In
general, the steps are as follows: an injection mold is prepared,
having the general characteristics that will result in a device
shown in the drawing sections. The superelastic/shape memory
elements are placed at desired locations in the mold. The desired
polymeric material is then injected into the mold with the elements
in place, prevented from moving, so that they are integrated into
the mold. The injected material is allowed to cure, and the device
(with the elements) is removed.
[0317] Any area or region of the device may be biased in a
direction (or directions) to increase the contact or
holding/compression force, or for other purposes, than without the
biased configuration (increase compression force) once the device
has been deployed (or when the bypass graft is loaded onto the
device, in the case of the stem).
[0318] A compliant material may be added to any or all areas of the
device (stem and or petals), to aid sealing between the vessel and
the device (similar to a gasket). For example, the compliant
material may be applied to the region in between the inner and
outer petals, and or one or both of the inner and outer vessel
petals. The compliant material may also have one or more grooves,
slots or other, to assist with hemostasis, prevent slippage, and or
any other purpose. The compliant material may be, or contain, an
adhesive or therapeutic substance. The compliant material may be
added to the device by dip coating, spraying, brushing, molding,
combination or any other method.
[0319] The stem may be over-molded or have a second piece jacket
that would have a lip or other feature that would contact the top
of the vessel, to prevent, or stop the vessel from splitting, as
well as to reinforce the anastomotic site. Adhesive may be located
on the bottom, vessel-contacting surface, or may be applied after
deployment. If the piece is separate from the device, it may be
placed around the bypass vessel before the to ends are secured, or
placed from the side (slot or slit through the side of the piece).
The tissue contacting area may be biased in such a way (downward)
that may increase the tissue contacting force. Jacket may be
reinforced with SE/SM materials, or other, and may be over-molded
with siliconee, ePTFE, combination or other biologically acceptable
material.
[0320] Each tissue-contacting element (petal) may have one or more
elements. One element may be deflected forward during deployment,
with another element, or section of an element, acting as a depth
stop to limit insertion. The deflected element may engage the
interior of the host vessel.
[0321] The host vessel tissue contacting elements(s) may be part of
the coupler, separate piece, or combination.
[0322] The host vessel tissue contacting elements may be flat,
concave, convex, combination or other, at any location.
[0323] The host vessel tissue contacting elements may have a
radiused (full or other), square, "V," combination, or other tip
geometry.
[0324] Each host vessel tissue contacting elements may have an
inside and outside vessel section, compressing the vessel wall in
between. There may be a radiused (or other shape) cut out in the
device to better "seat" the end of the vessel in between the host
vessel tissue contacting elements. This may also allow the host
vessel tissue contacting elements to lay flatter against the vessel
wall.
[0325] The petals (or horizontal Host vessel tissue contacting
elements) may have one or more curves ("S," or other shape or
configuration), to increase the contact area with the vessel, or
other purpose.
[0326] A suture (commonly used, NiTi, coil, combination or other)
may be used to secure the device to the bypass vessel, device to
the host vessel, or both. The host vessel tissue contacting
elements may have features such as holes, slots, cut outs reduced
width, combination or other, specifically designed to accommodate
any type of suture or clip. Alternatively, a standard design device
could be used with sutures, at any location, bonding, or assisting
with the bonding, of the vessels and the device.
[0327] An odd or even number of host vessel tissue contacting
elements may be used--matched pairs or other configuration.
[0328] Longer and shorter host vessel tissue contacting elements
may be used on the same device--they don't have to all be the same
length.
[0329] The "Bite and Lock" design for one of the tissue penetrating
versions of the device--the ends and or sided of the host vessel
tissue contacting elements may be designed to fit and lock together
during or after deployment.
[0330] The external side host vessel tissue contacting elements for
the coronary version may extend onto the epicardium. Side host
vessel tissue contacting elements may be partially, or completely
(substantially) flat. The side host vessel tissue contacting
elements may have adhesive on the tissue contacting surfaces, a
suture, combination or other may also be used to enhance the
contact between the device and vessel wall.
[0331] The desired host vessel tissue contacting elements are
deflected forward, and the "C" section of the deployment tool is
snapped, or positioned (from the side or top) around the desired
host vessel tissue contacting elements of the device.
[0332] Simple, disposable, hand-held tool, designed to deflect one
or more Host vessel tissue contacting elements (and or Host vessel
tissue contacting elements component) forward during insertion into
the host vessel (deployment) and be removed from around the host
vessel tissue contacting elements (see drawings previously sent).
The "C" section (constraining) of the tool may have weakened areas
(reduced wall and or width) that assist in removing the simple
deployment tool from the device (acting as a hinge). The tool may
also have a means to separate the anastomotic device from the
deployment tool, such as a pin that could pass through the
deployment tool, contacting and pushing the device from the tool,
as the pin or other is depressed.
[0333] The deployment tool may be plastic, and or have plastic,
rubber, or other non-metallic surface at the device contact areas
so as not to scrape, or otherwise remove the oxide from the surface
of the NiTi device.
[0334] The deployment tool may incorporate a tissue-stabilizing
feature, to assist deployment on a beating heart (features and
designs may be similar to those produced by Medtronic, Guidant or
other, and may include vacuum and or mechanical, or other,
stabilization).
[0335] The vascular couplers described herein can provide numerous
advantages. For example, the couplers can be a single piece
coupler. No collar may be required to secure a bypass vessel to the
coupler. The primarily metallic coupler has interior and exterior
vessel engagement/supports on the same host vessel tissue
contacting elements. Some versions of the couplers do not require a
deployment tool and can be inserted and secured by hand. The
deployment devices and methods do not expand, dilate, enlarge or
otherwise exert radial force on the arteriotomy or aortotomy. No
sheath is required for deployment of the couplers. The deployment
system engages and releases the couplers from the side, not through
a circumferential sheath. For the primarily metallic coupler, some
of the host vessel tissue contacting elements are deflected forward
for deployment, and some are left in the as annealed position,
which acts as a depth stop to prevent over insertion of the coupler
into the vessel. The overmolded ridge covers, and can be bonded to
the tissue surrounding the arteriotomy or aortotomy, reinforcing
the area and preventing any enlargement of the vessel access punch
or incision. The coupler host vessel tissue contacting elements
design compensates for any irregularities in the arteriotomy and or
aortotomy, as well as the vessel wall.
[0336] In general, the stem of the vascular couplers may be over
molded straight, sinusoidal, a combination of these configurations,
or any other suitable geometry. For example, to increase the
compliance of the vascular couplers, the stem may be formed with
longitudinal slots that run the length of the stem but do not cut
entirely through the stem. The stem also can be configured as a
surface for suturing the coupler to the bypass vessel wall. As with
other areas on the coupler, holes, slots, grooves, reduced wall
sections, or other openings or slots may be included on the stem to
locate a running or interrupted suture or assist the physician's
use of a running or interrupted suture.
[0337] In some of the above configurations, the overmolded stem may
have a groove, slot, and or slit in-between the inner and outer
wall of the stem. This space may be used to insert and secure a
bypass vessel or a bypass graft to the coupler, using an
interference fit, compression, adhesively bonded, suture, or
combination of these or other suitable connecting means.
[0338] The circumferential ridge (i.e., outer vessel ridge) may be
an integral part of the stem or may be a separate piece that is
separately molded or adhered to the stem. The circumferential ridge
functions as a top vessel contacting ridge to reinforce the
anastomotic site, as well as to act as a depth stop to limit
coupler insertion into the artery. The ridge can be completely or
partially circumferential and may be reinforced (as described
below). The ridge also can have a threaded region, such as a
diagonal slot through the ridge, which allows a twisting movement
to back out the ridge from inside the vessel during a push
in--partially pull out deployment method. The ridge also can
function as a surface for suturing the vascular coupler to the host
vessel wall. As with other areas of the coupler, the ridge can
include holes, slots, grooves, reduced wall sections, or other
openings to locate and assist in the use of a running or
interrupted suture. The vascular couplers above can be modified
such that the ridge can be used with a suture, or to better enable
suturing, to attach the bypass to the host vessel. In place of or
along with the suture, an adhesive may be used as previously
described. For example, a woven Dacron fabric can be adhered to the
ridge such that vessel can be sutured or adhered to the Dacron
fabric to attach the vessel to the ridge. Moreover, to assist with
acute hemostasis, a compliant "gasket" can be molded or adhered
under the over molded ridge--the gasket may also be part of the
over molded component. The gasket can be, for example, the same
material as previously described, including silicone, polyurethane,
combination or other suitable material. Moreover, as described
above, the bypass vessel or bypass graft may be attached to the
inside, outside or in-between the stem of the vascular coupler. The
attachment between the bypass graft and coupler may be completely
based on or augmented by a mechanical interference fit, one or more
sutures, an adhesive, a combination of these methods, and/or any
other suitable method.
[0339] One or more sections of the ridge, as well as the entirety
of the over molded section of the coupler, may include a
reinforcing layer or layers of material, such as woven Dacron,
ePTFE, a combination of these, or other suitable material. The
materials strengthen the ridge, thereby reinforcing or preventing
the suture from pulling out and away, which may split the compliant
ridge. The reinforcement material may be positioned on the top,
bottom, in between, or combination of sections of the ridge and/or
overmolded section or sections of the coupler. The suture
reinforcement also may be formed in the shape of a partial or
complete hoop or other structure.
[0340] In general, the multiple element version of the coupler may
be fabricated with individual petals or petals that are formed as a
group of more than one petal. The vascular coupler may be
fabricated by over-molding of, e.g., a polymer to secure the petal
or petal groups together to form the stem of the coupler. The
petals or petal groups may also be joined together with a hoop
configuration that may be split (i.e., open), completely closed
circumferentially, or other configuration between these two
configurations before being over molded. The coupler petals may be
fabricated as part of the stem, attached to the stem, and/or as
separate pieces which are then joined to the stem. The end of the
petals that are oriented away or outwardly from the stem can be
further away (i.e., wider) as they extend from the stem.
[0341] By using multiple independent petals, the vascular coupler
advantageously is configured for complete or greater than
circumferential vessel contact at the site of the aortic punch or
core site, and the arteriotomy for the coronary anastomosis.
[0342] As described above, the stem and petals may be fabricated
from a material that has a round, flat, concave, or convex
geometry. Of course, materials of other geometries can be used.
Similarly, although the overmolded vascular coupler has been
illustrated using individual petals, the petals described
previously (e.g., paper clip, two elements on one petal) also may
be used with the over molded versions of the coupler.
[0343] The petals for the over-molded version can be formed as
coils and advantageously have very minimal foreign material on the
inside of the vessel. The coil wire used to fabricate the petals
can be round, oval, or a combination of these or other geometries.
Similarly, the coil wires may be made from single or multiple wires
or a combination of these configurations or other continuous or
interrupted wire configurations.
[0344] The coil wind angle may be consistent, and or varied. In
this manner, the wider the separation between the coil winds, the
more flexible the section (or region) in which the coil winds are
positioned.
[0345] One, nearly complete circumferential loop (or other) of wire
from the coupler provides the interior vessel contact. More than
one wire may be used to create multiple, independent, partial
circumferential vessel contacting elements that together may be
nearly, or more than 360 degrees or other.
[0346] The coil wire used to fabricate the petals can be made of a
material as described herein. For example, in version, the material
may be a NiTi wire that has been electropolished and heat formed
(as disclosed in detail above) around a suitable fixture or
tool.
[0347] If a coiled strain relief is located above the over-molded
stem, the coil strain relief may be on the inside or outside of the
vessel and be secured with an adhesive, suture, or other attachment
means, as described above.
[0348] In general, the vascular coupler can be deployed using a
number of methods. For example, the vascular couplers may be
deployed using any of the tools and techniques describe above.
Examples of suitable method include the push in-pull out deployment
technique, deflecting forwardly the interior vessel components,
rotating the coupler during insertion, deploying by hand, and/or
compressing the stem,
[0349] Radiopaque material such as barium sulfate, bismuth
trioxide, tantalum or other can be added to the vascular couplers
described herein, reinforcement structure or bonding material.
Additionally, platinum, gold, or other material may be added to the
device by sputter coating, ion deposition, vapor deposition,
combination, or other process.
[0350] The connecting tube may have reference markings, and or a
larger diameter section to abut up against the edge of the stem, or
other method to confirm that the tubing end has been fully
inserted, and that the valve is in the open position.
[0351] In general, the bypass vessel can be attached to the
vascular couplers and the vascular couplers can be attached to the
host vessel using using sutures, staples (e.g., tissue penetrating
and or non tissue penetrating), clips (e.g., tissue penetrating and
or non tissue penetrating), adhesives, mechanical compression,
combination or other. The bypass graft can be attached to the
vascular couplers on the outside, inside, or in between.
[0352] In general, the securing members for the couplers described
herein can be tissue penetrating or non penetrating. The securing
members can be any shape, such as flat, round, concave, convex,
oval, combination or other. The securing member(s) may have a
single end, or a "U," "V," or other shape, including a "paperclip"
type configuration. The securing members may be separate individual
pieces, or attached to the petals, and overmolded. Alternatively,
the securing members (individual or attached to the petals or
other) may be separate from the coupler and crimped, allowed to
self recover (for the superelastic/shape memory version) or
otherwise bonded to the coupler. The securing member(s) may be
connected to the petals (single piece), and or stem, or may be a
separate element, or combination. The securing member(s) may be in
the shape of a "J", "U" or other suitable shape or design. For "U"
or other type securing member(s) that are separate from the coupler
prior to attachment, the overmolded ridge may have a section (or
sections) removed, to allow the outside of the securing member(s)
to be of longer length, and lay against the coupler surface. The
securing members may have horizontal and or diagonal (or other)
slots, grooves or other, on one or more surfaces, to prevent
slippage. Adhesive may also be used to assist the securing members'
attachment to the tissue, or to the coupler. Deformable securing
member(s) may be separate, independent piece(s) that are used to
attach the bypass vessel to the coupler, and are applied using a
hand tool (crimper, or other). Superelastic/shape memory securing
member(s) may be separate, independent piece(s) that are used to
attach the bypass vessel to the coupler, and are applied using a
hand tool (crimper, or other). The securing member(s) may be
designed and used to penetrate the tissue, compress the tissue
against the coupler, or combination. The securing member(s) may be
the same material as the petal and or stem, or different. The
securing member(s) may be a metal, metal alloy, combination or
other. The securing member(s) may be Nitinol, and automatically
compress the vessel to the coupler when a deflecting force (during
the loading process) is removed (through the
fixturing/annealing/quenching and repeating the process if
desired), or stainless steel (or other) that is bent, compressing
the vessel to the coupler. The securing member(s) may be metal,
metal alloy, or other as previously described for the coupler, or
coupler element. The securing member(s) may also be covered or
coated with an adhesive, biocompatible material, therapeutic
material, combination or other, as previously described. Any bare
metal on the securing member(s) may be electropolished.
[0353] The securing members may be overmolded with the coupler
instead of separate members. As previously disclosed, the bypass
vessel can be placed on the inside or outside of the stem (may be
the same or different version of the coupler, and or securing
member(s), depending on if the vessel is on the inside or outside
of the stem). If the vessel is placed on the inside of the coupler,
the securing member(s) may be held open (deflected) with a tool,
fingers, and or fixture. The distal vessel edge is positioned,
against or near the securing member(s). The deflection force is
removed, allowing the securing member(s) to return to the annealed
configuration, compressing the vessel wall against the coupler
body. The same configuration can be used or modified for use when
the bypass graft is on the outside of the coupler stem.
[0354] One or more bendable securing members can be used to attach
the graft to the coupler. In this case, the bypass vessel can be
placed on the inside or outside of the stem (may be the same or
different version of the coupler, and or securing member(s),
depending on if the vessel is on the inside or outside of the
stem). If the vessel is placed on the inside of the coupler, the
vessel is positioned against or near the securing member(s). The
securing member(s) may be in an open position, to assist with the
insertion and positioning of the vessel edge. Once positioned, the
securing member(s) may be bent against the vessel, compressing the
vessel against the coupler, by using a tapered dilator (or similar
instrument) inserted into the inner diameter of the coupler, until
the outer surface of the dilator contacts and forces the securing
member(s) against the vessel. If the vessel is placed on the
outside of the coupler, the vessel is positioned against or near
the securing member(s). The securing member(s) may be in an open
position, to assist with the insertion and positioning of the
vessel edge. Once positioned, the securing member(s) may be bent
against the vessel, compressing the vessel against the coupler, by
using fingers or a tool.
[0355] The inside diameter of the coupler may be straight, flared,
combination or other.
[0356] No dilating member needed or required before or during the
deployment of the coupler.
[0357] The petal element(s) of the overmolded coupler may be
movable through, or alongside, the wall of the overmolded body
during deployment. While the coupler is positioned over the incised
(or punched) vessel, the proximal ends of the petal elements may be
advanced (one at a time, more than one, or all at once) through the
stem, with the distal petal end protruding through the bottom of
the coupler, advancing into the vessel and coming into contact with
the vessel wall. The proximal ends of the petal elements may be
secured in place by mechanical interference fit, adhesive,
combination or other suitable designs or methods. This embodiment
would work well with petals made from Superelastic or Shape Memory
materials (specifically, but not limited to, nitinol) When using
petals (or other coupler component(s)) made from shape memory
nitinol, the petals (and or other component(s) may be activated to
bend/expand outward and engage the host vessel, from a straight or
other configuration, by temperature when the petals come in contact
with blood. The petal elements may be flat, angled, concave,
convex, combination or other geometry. Individual petal elements
may be grouped together with more than one petal, for example
within the overmolded section or sections of the coupler.
[0358] The tissue securing members may be assisted by the use of an
adhesive, interior coupler geometry, combination or other, to
provide a fluid tight seal between the bypass graft and coupler.
The securing members further may be activated to contact/secure the
bypass graft to the coupler by temperature (shape memory), when
using securing members made from nitinol. The securing members may
be initially bent using a dilator-like tool, and followed up with a
hemostat or other similar instrument, to further bend the securing
members against the vessel wall. The securing members may be
incorporated in the metallic tube version of the coupler. The
securing members may be formed at the same time as the petals are
formed (laser, wire EDM, chemical etching, combination or other)
from the tubing. Alternatively, the securing members may be
separate pieces.
[0359] The overmolded coupler may be formed over the petals,
securing members, etc., or molded as a separate piece and the
various components (such as petals, securing members, etc.) added
as a second process. The overmolded coupler and or tissue
contacting/reinforcing ridge sections may contain pores or holes
through the wall, sufficient to feed new intima growth from outside
of the vessel, so that endothelial cells may attach, or for any
other purpose. The pore size may be in the range of 5 to 80
microns, with 30 microns being optimum. The pores or holes in the
structure may be inherent in the material, present as the result of
weaving, braiding, expanding material processing (such as ePTFE) or
other process or method, or produced as a secondary process, such
as laser, or by any other suitable process. The overmolded body may
be produced by using a sintering process around any coupler
component. The overmolded section or sections may contain holes,
grooves, slots reduced thickness areas, combination or other, to
modify the rigidity/flexibility/compliance of the section or
sections, or for any other reason.
[0360] If a hemostatic gasket is used, it may be part of the
overmolded body, tissue contacting/reinforcing ridge or any other
component. Alternatively, it may be a separate piece. The gasket
may be made from any of the previously disclosed materials, and or
any suitable material. Any portion of the gasket may be flat,
concave, convex, combination, or any other suitable geometry.
[0361] The top vessel reinforcing ridge may be part of the
overmolded body, or a separate piece. The top vessel reinforcing
ridge may be biased toward the vessel, to increase the compression
between the vessel wall. Top vessel reinforcing ridge may prevent
the coupler from rotation once deployed/implanted. The top vessel
reinforcing ridge may be a different geometry and or material than
the coupler stem. The top vessel reinforcing ridge may be oval or
elongated, to be parallel with the vessel (coronary for example).
The top vessel reinforcing ridge may be flat, angled, concave,
convex, combination or other geometry. When viewed from above, the
top vessel reinforcing ridge may be completely circumferential, an
incomplete circle, sinusoidal, and or have one or more cut out
areas (for crimped securing members, flexibility, or for any other
purpose). The top vessel reinforcing ridge may have protrusions, on
the tissue contacting surface that may be of sufficient length, and
may be employed to prevent/limit coupler rotation once deployed
onto (into) the host vessel.
[0362] Holes, slots, grooves, concave areas or regions, or other
shapes may contain a therapeutic agent, bonding agent, combination
or other, on or inside any section, region or component of the
coupler. Materials, coating or coatings may be contained or applied
to any area, region or component of the coupler to reduce or
prevent post implant adhesions. Any coupler surface may be textured
for any purpose (such as to encourage neo intimal, and or
endothelial growth). When using deformable securing members to
secure the bypass graft to the coupler, the crimping tool (modified
hemostats or other) may have a stop, or other, to limit the amount
the securing member can be compressed, to prevent over crimping and
damage or weakening to the securing member that may result.
[0363] The coupler regions/components may be produced from
different materials with different physical properties. For
example, the external vessel ridge may be completely or partially
made from a softer or harder material than the stem.
[0364] The petals produced from a sheet (for example using chemical
etching or other as previously described), may include a secondary
process to join at least one section to another section (one edge
to a second edge or end). The secondary process may include
inserting one end (including a tab) into a slot, groove, hole or
other, soldering, welding, adhesively bonding, combination or other
suitable process. Alternatively, the section or sections may not be
bonded, or other wise attached together. This design may allow
additional flexibility at one or more regions of the coupler
(overmolded or non-overmolded).
[0365] The top vessel reinforcing ridge may have the same, smaller
or larger diameter as the deployed petals. The ridge may have at
least one section or surface that is flat, concave, convex,
combination or any other suitable geometry, to provide/assist with
the vertical compression for coupler securement and or acute
hemostasis.
[0366] The stem/strain relief may be produced in one configuration,
and designed to bend or deflect, but not kink, once a bypass graft
has been attached to the coupler and implanted into a host vessel.
For example, the coupler stem and or strain relief may be produced
at a 90.degree. angle, but deflect (again without kinking) to
approximately 45.degree.. This may be accomplished by reducing or
eliminating at least one section or region in the wall of the stem,
or alternatively, reinforcing at least one section or region of the
stem/strain relief wall. The stem/strain relief may include an
elbow or other suitable geometry--straight or combination. The
stem/strain relief may be any angle (measured from the reinforcing
ridge to the end of the stem/strain relief), and may be the same or
different than the angle between the petal and the reinforcing
ridge. For example, the vessel petal and the exterior reinforcing
ridge may be aligned so that the outside edges of each are
parallel, while the angle of the stem/strain relief may be at a
45.degree. (or other suitable) angle.
[0367] The stem, strain relief, overmolded ridge, combination or
other section, region or area of the coupler may contain at least
one component or element, designed for any desirable purpose
including the ability to expand and contract, producing a kinetic,
dynamic, radial spring action, and or response to deflection,
similar to a natural or sutured anastomosis.
[0368] The coupler may be packaged already attached to the
deployment tool. Alternatively, the coupler could be
inserted/attached/loaded in the deployment tool just prior to
deployment.
[0369] Another coupler fabrication method includes stereo
lithography (3-D layering) to partially or completely produce any
or all coupler component(s) (stem and ridge section for example).
The stereo lithography process may envelop/secure at least one or
more tissue contacting elements, or other components that may be
covered, partially or completely by the SL process. The process may
also produce cavities for the later insertion/securing of coupler
components (securing members/petals, etc.) as a secondary
process.
[0370] The types of couplers described herein can be coronary,
aortic, peripheral, valved, and other. The versions can be end to
side, end to end, side to side. The coupler groups include
sutureless or sutured. The coupler design options may have a
diameter: 1.0 mm to >8 mm; geometry: Concentric, oval,
combination or other, angle: 20.degree. to 90.degree. or other, and
stem length: 0 mm to 8 mm or larger. The deployment methods
include: (1) Compression of stem (using fingers or tool); (2)
Forward deflection of inner vessel elements; (3) Remove simple tool
from around coupler side, allowing superelastic petals to return to
non-constrained configuration, engaging vessel wall; (4) shape
Memory petals recover to annealed position once inside vessel
(using the bodies own heat, or by using a secondary heat source);
(5) Push in, partially pull out; (6) Twist during insertion; and
(7) Remote deployment devices and methods of use (to enable use of
coupler during minimally invasive, endoscopic, laparoscopic,
robotically assisted, catheter-based, as well as other types of
procedures).
[0371] While several particular forms of the invention have been
illustrated and described, it will be apparent that various
modifications can be made without departing from the spirit and
scope of the invention. For example, references to materials of
construction, specific dimensions, and utilities or applications
are also not intended to be limiting in any manner and other
materials and dimensions could be substituted and remain within the
spirit and scope of the invention. For example, the everted
verstions of the couplers without petals but having reinforcing
ridges, described herein, can be joined together. The ridges are
adhered together, as described herein, and the everted edges of the
vessels are thereby placed in contact to provide an end-to-end
anastomosis. Accordingly, it is not intended that the invention be
limited, except as by the appended claims.
* * * * *